WO2010041463A1 - Base station device and distance measuring method - Google Patents

Base station device and distance measuring method Download PDF

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Publication number
WO2010041463A1
WO2010041463A1 PCT/JP2009/005276 JP2009005276W WO2010041463A1 WO 2010041463 A1 WO2010041463 A1 WO 2010041463A1 JP 2009005276 W JP2009005276 W JP 2009005276W WO 2010041463 A1 WO2010041463 A1 WO 2010041463A1
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WO
WIPO (PCT)
Prior art keywords
tag
reader
base station
wireless terminal
signal
Prior art date
Application number
PCT/JP2009/005276
Other languages
French (fr)
Japanese (ja)
Inventor
深川　隆
木村　恭也
中川　洋一
裕人 向井
Original Assignee
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Priority to JP2010532826A priority Critical patent/JP5422564B2/en
Priority to US13/059,363 priority patent/US8659477B2/en
Publication of WO2010041463A1 publication Critical patent/WO2010041463A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
    • H04W64/006—Locating users or terminals or network equipment for network management purposes, e.g. mobility management with additional information processing, e.g. for direction or speed determination
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/76—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted
    • G01S13/765—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted with exchange of information between interrogator and responder
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/46—Indirect determination of position data
    • G01S2013/466—Indirect determination of position data by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices

Definitions

  • the present invention relates to a base station apparatus and a distance measuring method for measuring a distance from a wireless terminal in a wireless distance measuring system using a wireless technology such as UWB (Ultra Wide Band) wireless.
  • a wireless technology such as UWB (Ultra Wide Band) wireless.
  • wireless communication is performed between a wireless terminal such as a tag and a base station such as a reader, and a reflected signal in which an identification code (identification ID) of the wireless terminal is multiplexed is received at the base station. Propagation time and direction are detected. Thereby, the distance measurement between the wireless terminal and the base station and the position measurement of the wireless terminal are performed.
  • a wireless ranging system it is necessary to configure the system in consideration of characteristics of radio waves used for measurement in order to increase the reliability and accuracy of the measurement result.
  • Patent Document 1 As a conventional ranging device using UWB radio, as shown in Patent Document 1, using IEEE802.15.4a packet, communication operation, ranging operation and ranging operation (radio wave propagation) Detecting changes or movement in the environment and tracking objects) are known.
  • the transmission format used in this patent document 1 is shown in FIG.
  • the reader detects the position and movement of the tag in the radio wave propagation environment by using a specific preamble structure included in the IEEE 802.15.4a packet.
  • a series of packets including one preamble is received by the reader, and the preamble in each packet is despread. Then, the reference multipath profile is updated, and the “current multipath profile” of the packet currently received is obtained. By comparing the “current multipath profile” with the “reference multipath profile”, an object in the radio wave propagation environment is detected. In addition, the ground scatter (Ground Scatter), that is, the strongest ground reflected wave as a reflected wave in an open ground without a wall surface or the like is removed, and the position, movement, etc. of the object are detected.
  • Ground Scatter the ground scatter
  • the “current multipath profile” of each packet is obtained from the preamble in each packet subsequent to the received packet.
  • a scheme for comparing a “current multipath profile” of a packet with a “reference multipath profile” is shown.
  • ground scatter assumed in the conventional configuration is ground reflection
  • the ground reflected wave occupies the majority of the signal received by the reader
  • the ground reflected wave is delayed in the reader from the reflected signal from the passive tag. It is detected as a large signal.
  • a delay profile in a specific time domain can be easily removed based on the geometric relationship.
  • a radio wave propagation environment in which a reflected wave from a wall closer to the reader exists than a tag (desired tag) whose ID is to be detected, or a plurality of tags It is assumed that there is a radio wave propagation environment.
  • the detected head wave is not necessarily a reflected signal from a desired tag. That is, the leading wave may be an unnecessary wave.
  • an unnecessary wave and a reflected signal from the tag sequentially arrive as a plurality of pulses. Cannot be easily identified.
  • the present invention has been made in view of such points, and even when IR-UWB is used for distance measurement, a reflected signal from a desired tag and an unnecessary wave can be easily identified, and accuracy of distance measurement is achieved. It is an object of the present invention to provide a base station apparatus and a distance measuring method that can improve performance.
  • the base station apparatus of the present invention comprises a reader ID indicated by a code string consisting of P bits (P is a natural number) for identifying the base station apparatus, and Q bits (Q is a natural number) for identifying the wireless terminal.
  • Generating a unique word generating a frame including 2 ⁇ M unique words, generating a burst including Q frames, and outputting a transmission signal including a plurality of the bursts; and the radio
  • the terminal modulates the signal obtained by modulating the transmission signal based on whether each of the Q bits indicating the tag ID is 1 or 0 by 1 / M of the transmission clock cycle (M is an integer of 1 or more).
  • M is an integer of 1 or more.
  • the distance measuring method of the present invention comprises a reader ID indicated by a code string consisting of P bits (P is a natural number) for identifying a base station apparatus, and Q bits (Q is a natural number) for identifying a wireless terminal.
  • P is a natural number
  • Q is a natural number
  • Generating a unique word in which pulses are modulated on and off generating a frame including 2 ⁇ M unique words, generating a burst including Q frames, and outputting a transmission signal including a plurality of the bursts;
  • a wireless terminal phase-shifts a signal obtained by ASK-modulating the transmission signal based on whether each Q bit indicating the tag ID is 1 or 0 by 1 / M (M is an integer of 1 or more) of the transmission clock period. At different times and to sample received.
  • IR-UWB IR-UWB
  • a reflected signal from an intended tag and an unnecessary wave can be easily identified, and the accuracy of distance measurement can be improved.
  • the figure which shows the transmission format of patent document 1 Diagram showing radio wave propagation environment 1 is a block diagram showing the configuration of a distance measuring device according to Embodiment 1 of the present invention.
  • leader shown in FIG. 3 transmits Diagram showing an example of tag transmission format Diagram showing the relationship between burst sequence and delay profile Diagram showing operation of phase shift sampling
  • FIG. 2A is a schematic diagram showing an example of a radio wave propagation environment. It is desirable that the radio wave transmitted from the reader 201 as the base station is received again as a reflected signal by the reader after the tag ID for identifying the tag itself is added in the desired tag (TAG1) 202.
  • TAG1 desired tag
  • the desired tag TAG1
  • the reflector include another tag (TAG2) 203, a wall surface 204, a reflector 205 that exists near the reader, and a reflector 206 that exists far from the reader. Reflected waves from these reflectors are detected as different delay profile peaks on the delay profile observed by the reader 201.
  • the transmission signal transmitted by the reader 201 has a pulse train 210 periodically transmitted as shown in FIG.
  • a peak 213 indicating a reflected wave from the distant reflector 206 and a peak 214 indicating a reflected wave from TAG2 are detected.
  • FIG. 2C is an example, as shown in this figure, the peak 211 of the leading wave having the highest level is not a reflected wave from the desired tag (a signal to which the tag ID of TAG1 is added). It is possible.
  • the leading wave 211 is a reflected wave from the adjacent reflector 205, and thus this signal needs to be removed. Since there are a plurality of tags, the reflected wave (peak 212) to which a desired tag ID is added and the reflected wave (peak 214) to which another tag ID is added need to be separated using these delay times. There is.
  • FIG. 3 is a block diagram showing the configuration of the distance measuring apparatus according to the embodiment of the present invention.
  • the tag 300 includes a tag reception antenna 301 and a tag transmission antenna 302. Note that these antennas may be shared by using a distributor, a circulator, or the like.
  • a transmission signal transmitted from the reader 310, for example, an IR-UWB pulse train signal is received by the tag receiving antenna 301.
  • a tag ID adding unit 304 of the tag 300 holds a tag ID assigned as an identification ID unique to each tag using a memory or wiring logic.
  • the ASK modulation unit 303 reads the tag ID held in the tag ID addition unit 304 and receives the tag ID from the reader using a code sequence (a code sequence including bit “0” and bit “1”) indicating the tag ID.
  • ASK modulation Amplitude Shift Keying Modulation
  • the tag 300 transmits a signal obtained by ASK modulation from the tag transmission antenna 302.
  • the operation of the ASK modulation unit 303 is similar to the operation of a general passive tag or semi-passive tag returning its tag ID to the reader by applying ASK modulation to the continuous carrier wave from the reader. .
  • the tag 300 performs ASK modulation on the pulse train signal transmitted from the reader 310 using the tag ID as follows. More specifically, the pulse train transmitted from the reader is returned as it is to the bit “1” constituting the code sequence of the tag ID. In addition, the pulse train transmitted from the reader is not returned to the bit “0” constituting the code sequence of the tag ID.
  • Such switching of whether or not to return a pulse train can be realized by the following method, for example.
  • the ASK modulation unit 303 can be realized by switching the tag receiving antenna end by mismatch or matching, or by connecting or terminating between the tag receiving antenna and the tag transmitting antenna.
  • the ASK modulation unit 303 can be realized by turning on / off a low noise amplifier circuit (LNA: Low / Noise / Amplifier) or a power amplifier.
  • LNA Low / Noise / Amplifier
  • a reader ID holding unit 313 of the reader 310 holds a reader ID assigned as an identification ID unique to each reader using a memory or wiring logic.
  • the transmission pulse generator 312 reads the reader ID held in the reader ID holding unit 313 and performs OOK (On-Off-Keying) modulation based on the code string of the reader ID.
  • a pulse train corresponding to the reader ID thus generated is periodically transmitted as a transmission signal from the reader transmission antenna 311.
  • the reader receiving antenna 314 receives a reflected signal (including a pulse train) returned from the tag 300 and added with a tag ID.
  • the reader ID correlation calculation unit 315 performs a sliding autocorrelation process between the reflected signal received by the reader receiving antenna 314 and the reader ID read from the reader ID holding unit 313, and generates a plurality of delay profiles corresponding to each cycle. To do.
  • the generated delay profile is output to the peak detector 316.
  • the peak detection unit 316 performs a peak search on the plurality of delay profiles output from the reader ID correlation calculation unit 315, and extracts reflected waves that are unnecessary waves and reflected signals transmitted from a plurality of tags. The extracted reflected wave and the reflected signal transmitted from the plurality of tags are output to the tag ID correlation calculation unit 318.
  • the tag ID holding unit 317 holds a plurality of tag IDs associated with the reader 310 in advance using a memory or wiring logic.
  • the tag ID correlation calculation unit 318 reads a desired tag ID from a plurality of tag IDs held in the tag ID holding unit 317, and correlates the read tag ID with the signal output from the peak detection unit 316. Process. By this correlation processing, the tag ID correlation calculation unit 318 identifies a delay profile that matches the desired tag ID, and detects a set of peaks of a specific delay time.
  • the leading wave detection unit 319 selects the peak of the delay profile with the shortest delay time (the leading wave of the tag ID). The detected peak is output to the delay time measuring unit 320.
  • the delay time measurement unit 320 compares the reference timing at which the transmission signal to the tag is transmitted with the timing at which the reflected signal from the tag is received, and the delay time, that is, the signal transmitted from the reader 310 is transmitted via the tag 300. Then, the time required until it is received again by the reader 310 is extracted. The extracted delay time is output to the distance calculation unit 321.
  • the distance calculation unit 321 calculates the distance between the tag and the reader using the delay time output from the delay time measurement unit 320.
  • FIG. 4 is a diagram showing an example of a transmission format transmitted by the reader 310 shown in FIG. FIG. 4A shows a pulse train transmitted from the reader transmission antenna 311. This is a pulse train generated by the transmission pulse generator 312 performing OOK modulation based on the code sequence of the reader ID held in the reader ID holder 313. Thereby, a pulse train corresponding to the reader ID is periodically transmitted.
  • the reader ID is represented using 128 pulses.
  • the number of pulses is not particularly limited as long as a plurality of reader IDs can be uniquely distinguished.
  • the criterion for determining the number of pulses corresponds to the number of readers accommodated in the system.
  • a PN code or GOLD code with high autocorrelation is used.
  • a series of 128 pulses representing the reader ID is referred to as a unique word (hereinafter referred to as “UW”).
  • UW unique word
  • FIG. 4B n UWs (n is 2 or more) are always processed as one set.
  • this one set is called a frame.
  • n (16 in this embodiment) UWs in one frame are processed as one set will be described.
  • the original oscillation that is the basis of each operation is not phase-synchronized, that is, asynchronous.
  • a slight frequency error occurs. Therefore, the tag that has received the transmission signal from the reader does not always send out the UW included in the transmission signal from the reader and the tag ID added to the reflected signal in a synchronized state.
  • the pulse width of the UWB pulse train is the same as the transmission clock cycle, and oversampling cannot be performed. Therefore, in order to reliably sample the reflected wave from the tag, it is preferable to sample the reflected wave after phase shifting the reception sampling timing with respect to the cycle of the transmission clock.
  • the waveform of the received signal is shaped like a triangular wave as compared to a square wave, so the received signal is phase shifted and sampled. It is effective.
  • the tag performs 1-bit ASK modulation for one frame. For example, when a tag transmits a 128-bit tag ID, it is necessary to transmit a continuous signal of a pulse train composed of 128 frames.
  • FIG. 4D shows 128 frames necessary for transmitting the tag ID as one burst.
  • a tag can send a tag ID once using one burst.
  • the number of frames constituting one burst is not limited to 128 as long as all the plurality of bits constituting the tag ID can be transmitted.
  • the reader can repeatedly transmit a pulse train of 128 pulses ⁇ 16 UW ⁇ 128 frames per burst, and process the tag ID using this burst. Since the transmission clock is a time reference, it is always a fixed period, but because the reception operation is sampled by the phase shift clock, the frequency is the same for both the transmission clock and the reception clock, but the timing (phase) of each clock is Different.
  • FIG. 5 is a diagram showing an example of a tag transmission format.
  • FIG. 5 shows a case where phase shift of reception sampling in the reader is not performed, that is, a case where one frame is 2 UW.
  • the timing at which the tag transmits the tag ID is not determined as one.
  • the tag ID code “0” (504) corresponding to the start bit is added by the tag 300 and transmitted to the reader 310 as a reflected signal at the timing of UW501.
  • One bit included in the code string constituting the tag ID is transmitted with one frame length, that is, here, a length corresponding to 2 UW. Therefore, even when the transmission timing of the frame transmitted by the reader is different from the transmission timing of the tag ID transmitted by the tag, the timing of one of the previous UW and the subsequent UW among the two UWs in the frame is , The code change point of the tag ID code (bit “0” or bit “1”) is applied.
  • the signal indicating the bit “1” or the bit “0” included in the code string constituting the tag ID is ASK-modulated and transmitted in one UW.
  • the reader transmits the tag ID code synchronized with UW.
  • the tag ID code corresponding to this UW is detected.
  • the reader does not use this UW for detection of the tag ID code.
  • the reader can detect the tag ID code constituting the tag ID by performing correlation processing on this UW.
  • the tag ID code “1” (505) and the tag ID code “1” (506) it is considered that the transmission timing of the tag ID is synchronized with the UWs 502 and 503 in the latter half of each frame. .
  • a tag ID that is considered to be synchronized with the first half UW may be transmitted.
  • the reader reception processing corresponding to FIG. 5 is performed by determining whether the reader ID correlation calculation unit 116 performs correlation processing on the UW and the peak detection unit 116 is synchronized with the first half UW, or the second half UW. Determine if it is considered synchronized.
  • FIG. 6 shows the relationship between burst sequences and delay profiles.
  • a delay profile of a reflected wave in which a reflected wave near, a tag ID transmission wave, a far reflection wave, and a tag ID reflection wave is reflected by a wall or the like is observed.
  • reference numeral 601 denotes a burst string detection result of a near reflection wave
  • 602 denotes a burst string detection result of a tag ID transmission wave
  • 603 denotes a burst string detection result of a far reflection wave
  • 604 denotes a burst string of a tag ID reflection wave. It is a detection result. Since 601 and 603 are reflected waves from the reflector, signal amplitude fluctuation does not occur with respect to the burst train.
  • reference numerals 602 and 604 are signals to which IDs transmitted from the tags are added by ASK modulation. Amplitude changes corresponding to the tag IDs are seen on a frame basis, and bar-code detection results are obtained.
  • the tag ID correlation calculation unit 318 correlates with the tag ID in the burst direction, and if a correlation is obtained, the detection results 602 and 604 are set as candidate bursts.
  • the leading wave detection unit 319 detects the leading wave of the delay profile as 602 among the candidate bursts.
  • the delay time measurement unit 320 calculates the transmission reference timing on the delay profile and the detection time of the desired tag ID that is the output of the leading wave detection unit 319, and measures the delay time.
  • FIG. 7 is a diagram showing the phase shift sampling operation.
  • reference numeral 701 denotes a waveform of a transmission signal from the reader
  • reference numeral 702 denotes a waveform of a signal received by the reader.
  • the signal waveform 702 is different from the signal waveform 701 and has a different signal amplitude due to the UWB band limitation.
  • phase shifts 1 to 8 indicate the sampling timing, but this timing is different every time it is received. For this reason, in this embodiment, before the reader ID correlation calculation unit 315 obtains signal correlation with its own reader, all eight phase components are added to increase the power.
  • the sampling is performed at the timing of phase shift by 1/8, but is not limited to 1/8.
  • a unique word in which each pulse is on / off modulated depending on whether each of the P bits indicating the reader ID is 1 or 0 is generated using the tag ID indicated by the code string consisting of A frame including 2 ⁇ M frames is generated, a burst including Q frames is generated, a transmission signal including a plurality of bursts is output, and the wireless terminal is based on whether each of the Q bits indicating the tag ID is 1 or 0
  • the UWB signal is used for ranging by sampling and receiving a signal obtained by ASK modulation of the transmission signal at a timing with a phase difference of 1 / M (M is an integer of 1 or more) of the transmission clock period.
  • FIG. 8 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 2 of the present invention.
  • the wireless ranging system includes a reader 800, a first tag 801, and a second tag 802.
  • the first tag 801 is mounted on the surface of the name tag 810 worn by the human 850
  • the second tag 802 is the position of the ring-shaped neck strap 803 connected to the name tag 810 and the position of the name tag.
  • the second tag 802 is attached to an intermediate portion of the neck strap 803.
  • the second tag 802 When the person 850 wears the name tag 810, if the name tag 810 is hung in front of the chest with the neck strap 803 on the neck, the second tag 802 is located at the rear part of the neck.
  • the tag 801 is disposed toward the front of the human body, and the second tag 802 is disposed toward the rear of the human body.
  • FIG. 9 is a block diagram showing the configuration of the reader and tag according to Embodiment 2 of the present invention.
  • the reader 800 is a wireless device using UWB, and any of a ranging method, an active method, a passive method, and a semi-passive method can be applied.
  • FIG. 9 shows a semi-passive configuration as an example.
  • the distance measurement between the tag and the reader using the tag and the reader is performed using the propagation time of the measurement signal transmitted and received between the tag and the reader. If the propagation time of the measurement signal is calculated and the propagation speed of the radio wave is added to the propagation time, the distance between the tag and the reader can be obtained.
  • the transmission radio wave from the reader is reflected or amplified and re-radiated, and the tag ID is transmitted as the tag identification ID. Thereby, based on the absolute reference time counted inside the reader, it is possible to calculate the round-trip time of the measurement signal that reciprocates between the tag and the reader.
  • the tag 900 includes a receiving antenna 901, a transmitting antenna 902, and a tag ID adding unit 903.
  • the reader 910 includes a transmission antenna 911, a transmission pulse generation unit 912, a timing signal output unit 913, a reception antenna 914, a pulse detection unit 915, a tag ID detection unit 918, a delay time measurement unit 916, and a distance calculation unit 917. Yes.
  • the reader 910 generates and outputs a reference timing signal at the timing signal output unit 913, and generates a UWB pulse for measurement according to the timing signal at the transmission pulse generation unit 912, and transmits the UWB pulse from the transmission antenna 911 to the space. Radiate.
  • the tag 900 receives the UWB pulse at the receiving antenna 901, and the tag ID adding unit 903 modulates the UWB pulse using a unique tag ID in each tag. As a result, an identification ID, which is ID information for tag identification of the own device, is added and transmitted from the transmission antenna 902.
  • the reader 910 receives a signal returned from the tag 900 at the reception antenna 914 and detects a UWB pulse at the pulse detection unit 915.
  • the tag ID detection unit 918 detects the tag ID from the UWB pulse, and performs individual recognition of the person wearing the tag.
  • the delay time measurement unit 916 measures the delay time of the UWB pulse returned from the tag 900 with reference to the timing signal of the timing signal output unit 913, and the distance calculation unit 917 measures the measured delay time of the UWB pulse. Based on the above, the distance between the reader and the tag is calculated.
  • a measurement signal including ID information is transmitted at the timing when the tag is synchronized with the reader in advance, or when the tag and the reader are not synchronized, the clocks of a plurality of readers are synchronized. Then, a measurement signal including ID information is transmitted from the tag to a plurality of readers, and a difference in time required until the measurement signal arrives is obtained. Thereby, distance measurement between the tag and the reader can be performed from the relative propagation time (propagation time difference) in each reader.
  • the tag position can be measured by the principle of three-point surveying. Further, when the reader has a function of measuring the arrival direction of radio waves, the tag position can be measured from the arrival direction of radio waves and the distance between the tag and the reader even if there is only one reader.
  • the transmission signal from the tag is greatly attenuated due to the shielding absorption effect of the human body.
  • the tag or tags are always present from the reader to the visible region on the human body.
  • the tags are arranged so that they are located, i.e. where at least one tag is visible to the reader. Then, the reader detects a tag ID transmitted from at least one tag among the plurality of tags, or measures a distance between the reader and the tag based on the tag ID.
  • the first tag 801 is mounted on the surface of the name tag 810.
  • a tag ID is assigned to the tag 801 as ID information for performing individual recognition of a person wearing the name tag 810.
  • the tag 801 enters the reception area of the reader 800, a signal including a tag ID is transmitted from the tag 801 to the reader 800.
  • the second tag 802 is attached to, for example, the center of a neck strap 803 connected to the name tag 810.
  • the second tag 802 When the human wears the name tag 810, the second tag 802 is positioned in contact with the back of the person's neck, so that the second tag 802 is attached to the name tag 810 on which the first tag 801 is mounted. On the other hand, it is mounted on the back side of humans.
  • the second tag 802 also has the same tag ID as the first tag 801.
  • the reader 800 detects the tag ID from the signal transmitted from the first tag 801 or the second tag 802 and recognizes the individual ID of the person wearing the first tag and the second tag. At this time, since either the first tag 801 or the second tag 802 is directed toward the reader 800 with respect to the reader 800, a plurality of signals transmitted from a plurality of tags are selected or synthesized. The tag ID is detected. In identifying the ID information, the reader 800 reads the tag ID, observes the reliability of the read ID based on the signal level, etc., determines the tag ID using highly reliable data, and performs individual recognition. .
  • the distance is measured by detecting the leading wave for the ID that seems to be the same as the identified tag ID.
  • the characteristics of the two tags are not specifically described.
  • the name tag when a tag is attached to a name tag and a string, the name tag has a larger area than a string.
  • the name tag can increase the degree of freedom in designing a tag such as an antenna, thereby improving the tag transmission power.
  • the reliability can be improved by preferentially identifying the radio wave transmitted from the tag of the name tag in the reader as the tag ID.
  • the tag attached to the name tag and the tag attached to the string can be identified by providing a flag in the data portion including the ID information.
  • a plurality of tags have been described as having the same tag ID, but may have different tag IDs. If the ID information is different for each tag, the tag having the same ID is registered by registering information indicating that a plurality of tag IDs are added to a person who has already attached the tag. The same operation and effect can be obtained by performing the same process as in the above.
  • the tag ID of the name tag may be registered in advance, and the reader may preferentially process the corresponding ID. .
  • the second tag may be arranged on the collar of clothes worn by humans.
  • the person to wear is decided like work clothes in a factory etc., if a tag having the same ID as the name tag is previously sewed on the back side portion such as the collar portion of the clothes, the same effect is obtained. can get.
  • the shielding / absorbing effect in the human body can be reduced, and when the UWB wireless or the like having a large human body absorption loss is used, the identification ID is transmitted / received between the tag and the reader, the distance measurement, and the positioning are reliable. It can be realized in a state with high performance.
  • FIG. 10 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 3 of the present invention.
  • the third embodiment is an example in which a tag is arranged on a human head.
  • the wireless ranging system includes a reader 800, a first tag 801, and a second tag 802. Similar to the first embodiment, the first tag 801 is mounted on a name tag 810 worn by a human 850.
  • the second tag 802 is attached to the helmet 1005 worn by the human 850. In the illustrated example, the second tag 1002 is attached to the top of the helmet 1005.
  • the second tag 802 is located at the top of the head, and includes the direction from the rear of the human body that is out of the visible region of the name tag 810 on the front side of the human body.
  • the tag 802 is disposed so as to be visible.
  • the helmet 805 is placed at a slight distance from the head to protect the human head from the impact of an object collision because the helmet 805 is at the top of the human body and is less likely to become a human figure. For this reason, in Embodiment 3, the characteristic deterioration by the shielding absorption effect in a human body and the human body effect of an antenna is further reduced.
  • the second tag 802 is usually the main ID acquisition and distance measurement tag, but it is also assumed that a person is taking off the helmet 805. In that case, the first tag is mainly used. ID acquisition and distance measurement are performed by the tag 801.
  • FIG. 11 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 4 of the present invention.
  • the fourth embodiment is an example in which tags are arranged before and after a human torso.
  • the wireless ranging system includes a reader 800, a first tag 1101, and a second tag 1102.
  • the first tag 1101 is mounted on a buckle portion or the like of the waist belt 1103 worn by the human 850
  • the second tag 1102 is mounted on a different position of the waist belt 1103, for example, at an intermediate portion of the waist belt 1103. Yes.
  • the first tag 1101 and the second tag 1102 are positioned before and after the waist belt 1103, and the first tag 1101 is disposed toward the front of the human body,
  • the second tag 802 is arranged toward the back of the human body.
  • the first tag 1101 is mounted at a position corresponding to a human abdomen by mounting it on the buckle portion, for example, in front of the waist belt.
  • a tag ID is assigned to the first tag 1101 as ID information for performing individual recognition of a human wearing the waist belt 1103.
  • the tag 1101 enters the reception area of the reader 800, the tag 1101 is connected to the reader 800. Then, a signal including the tag ID is transmitted.
  • the second tag 1102 is mounted on the back side of the human body with respect to the first tag 1101 by being mounted on the middle portion of the waist belt 1103 so that the second tag 1102 is mounted on the back or waist of the human.
  • the second tag 1102 also has the same tag ID as the first tag 1101.
  • the reader 800 detects the tag ID from the signal transmitted from the first tag 1101 or the second tag 1102 and recognizes the individual ID of the person wearing the first tag and the second tag. At this time, either the first tag 1101 or the second tag 1102 is directed toward the reader 800 with respect to the reader 800. In identifying the ID information, the reader 800 reads the tag ID, observes the reliability of the read ID based on the signal level or the like, and determines that the tag ID is highly reliable.
  • the first tag 1101 and the second tag 1102 are integrated with each other through the waist belt 1103 and are always attached to the front and back of the human body, thereby reducing the shielding absorption effect. Have
  • the waist belt is taken as an example.
  • the first tag and the second tag may be attached to the front and back of the human body using a suspender (suspending belt) or the like.
  • FIG. 12 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 5 of the present invention.
  • the fifth embodiment is an example in which tags are arranged on both human shoulders.
  • the wireless ranging system includes a reader 800, a first tag 1201, and a second tag 1202.
  • the first tag 1201 is attached to one shoulder of the clothes worn by the human 850
  • the second tag 1202 is attached to the other shoulder of the clothes.
  • the first tag 1201 and the second tag 1202 are located on both shoulders, the first tag 1201 is arranged toward the right side of the human body, and the second tag 1202 is arranged toward the left side of the human body.
  • the first tag 1201 and the second tag 1202 have the same tag ID.
  • first tag 1201 and second tag 1202 can be attached to left and right shoulder pads such as left and right shoulder pads and military uniforms of clothes and work clothes, for example.
  • the antenna directivity pattern of the tag mainly forms an upper hemispherical surface, particularly when the reader 800 is above the position of the human shoulder, It is hard to receive an effect.
  • radio waves are shielded and absorbed by the head, so the tag is attached to both shoulders as in the fifth embodiment in consideration of the effect of the head. Thus, shielding absorption by the head can be prevented.
  • FIG. 13 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 6 of the present invention.
  • the sixth embodiment is an example in which tags are arranged on both human arms and chest.
  • the wireless ranging system includes a reader 800, a first tag 1301, a second tag 1302, and a third tag 1303.
  • the first tag 1301 is attached to the left arm of the clothes worn by the human 850
  • the second tag 1302 is attached to the right arm
  • the third tag 1303 is attached to the chest.
  • the first tag 1301 and the second tag 1302 are located on both arms
  • the third tag 1303 is located on the chest
  • the first tag 1301 is located on the left side of the human body.
  • the second tag 1302 is disposed toward the right side of the human body
  • the third tag 1303 is disposed toward the front of the human body.
  • the first tag 1301 and the second tag 1302 are arranged, for example, on the left and right sleeve buttons, respectively.
  • the third tag 1303 is attached to, for example, a breast pocket.
  • the first tag may be a left sleeve button
  • the second tag may be a right sleeve button
  • the third tag may be a name tag.
  • the first tag may be a left sleeve button
  • the second tag may be a right sleeve button
  • the third tag may be a front button.
  • the first or second tag may be attached to the watch.
  • the antenna directivity pattern of the first tag is a left hemisphere
  • the antenna directivity pattern of the second tag is a right hemisphere
  • the antenna directivity pattern of the third tag is the front. It is thought to form a hemispherical surface. As a result, the effect of shielding and absorbing the human body between the reader and the tag can be reduced.
  • FIG. 14 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 7 of the present invention.
  • the seventh embodiment is an example in which tags are arranged on a human chest and feet.
  • the wireless ranging system includes a reader 800, a first tag 1401, and a second tag 1402.
  • the first tag 1401 is attached to a name tag 810 worn by a human 850
  • the second tag 1402 is attached to a heel portion of a shoe 1410 worn on a foot.
  • the first tag 1401 is located on the chest
  • the second tag 1402 is located on the foot
  • the first tag 1401 faces the front of the human body.
  • the second tag 1402 is arranged toward the back of the human body.
  • the first tag 1401 and the second tag 1402 have the same tag ID.
  • the antenna directivity pattern of the first tag is formed in the forward direction
  • the antenna directivity pattern of the second tag is formed in the backward direction.
  • the second tag 1402 is attached to the shoe heel portion, but may be attached to the shoelace portion.
  • the tag is not necessary to use a special attachment structure such as sewing the tag into the shoe, and it is easy to attach the tag to a general shoe later.
  • the antenna directivity pattern can be directed backward even when the tag is attached to the shoelace.
  • FIG. 15 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 8 of the present invention.
  • Embodiment 8 is an example in which tags are arranged on both sides of glasses worn by humans.
  • the wireless ranging system includes a reader 800, a first tag 1501, and a second tag 1502.
  • the first tag 1501 is attached to the handle portion on the right side of the glasses 1503 that the human 850 puts on the head, and the first tag 1502 is attached to the handle portion on the left side of the glasses 1503.
  • the antenna directivity pattern of the first tag 1501 forms a right hemisphere
  • the antenna directivity pattern of the second tag 1502 forms a left hemisphere. It is possible to reduce the effect of shielding and absorbing the human head at.
  • glasses include general goggles, ski goggles, defensive work goggles in factory work, and the like.
  • a plurality of tags such as a first tag and a second tag having the same ID, are provided at a plurality of locations such as front and back, left and right of a human, It is configured to be arranged in at least two locations (preferably 2 to 3 locations) selected from the front, back, head, feet, left side, and right side of a human.
  • at least one tag is arranged to face the base station, Wireless communication is possible without a human body between at least one tag and the base station.
  • the shielding / absorbing effect of the human body can be reduced, and signal strength deterioration due to human body absorption can be compensated.
  • a wireless ranging system such as a UWB reader tag device using UWB having a large human body absorption loss, highly reliable wireless communication can be performed, and tag ID transmission / reception and reader-tag distance measurement can be reliably performed. It becomes possible.
  • Embodiments 2 to 8 The technical idea derived from the description of Embodiments 2 to 8 is as follows.
  • a wireless terminal used in a wireless ranging system including a base station and a wireless terminal, and includes a plurality of tags, and each of the plurality of tags is an individual to which the wireless terminal is attached.
  • a signal including an identification ID for recognition can be transmitted, and when the wireless terminal is mounted on a human body, the plurality of tags are selected from the front, back, head, foot, left side, and right side of the human Wireless terminals arranged in at least two places.
  • the tag and the second tag have the same identification ID, and a signal transmitted from the first tag or the second tag is used for individual recognition of a person wearing the wireless terminal.
  • the wireless terminal according to any one of (1) to (3).
  • the wireless terminal is disposed on a waist belt worn by a human, and the plurality of tags are disposed at different positions when the waist belt is worn on a human body.
  • the wireless terminal according to any one of 3).
  • the plurality of tags include a first tag disposed on a right handle of glasses worn by a human on a head and a second tag disposed on a left handle (1) to ( The wireless terminal according to any one of 3).
  • the plurality of tags include a first tag arranged on a name tag of a person wearing the wireless terminal, and a second tag arranged on a collar of clothes worn by the person,
  • the wireless tag according to any one of (1) to (3), wherein the first tag and the second tag have the same identification ID.
  • a base station used in a wireless ranging system including a base station and a wireless terminal, each transmitting a signal including an identification ID for performing individual recognition of a wearing target as the wireless terminal.
  • a plurality of tags and when the wireless terminal is mounted on a human body, the plurality of tags are arranged in at least two locations selected from the front, back, head, foot, left side, and right side of a human. Communicating with the one, detecting the identification ID included in a signal transmitted from at least one of the plurality of tags, and based on the detected identification ID, the distance to the wireless terminal Measuring base station.
  • the identification ID is determined using highly reliable data, and the individual recognition of the human wearing the wireless terminal (15) or (16), wherein the distance from the wireless terminal is measured using the first wave of signals transmitted from the plurality of tags with respect to the same identification ID as the detected identification ID. Base station.
  • a plurality of tags are configured, and each of the plurality of tags can transmit a signal including an identification ID for performing individual recognition of a mounting target of the wireless terminal.
  • the plurality of tags communicates between the wireless terminal and the wireless terminal disposed at least at two locations selected from the front, back, head, foot, left side, and right side of the human
  • a base station that detects the identification ID included in a signal transmitted from at least one of the plurality of tags, and measures a distance from the wireless terminal based on the detected identification ID;
  • a wireless lateral distance system A wireless lateral distance system.
  • a wireless ranging system using a UWB wireless system having a plurality of tags as wireless terminals and a reader as a base station as wireless terminals and base stations used in the wireless ranging system Although such a configuration example is shown, such a wireless ranging system may be called a UWB reader tag device.
  • the present invention can be configured by hardware in each of the wireless terminal and the base station, and can also be realized by software.
  • each functional block used in the description of each of the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.
  • the name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.
  • the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible.
  • An FPGA Field Programmable Gate Array
  • a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.
  • the base station apparatus and distance measuring method according to the present invention can be applied to a tag locator attached to a remote controller, a name tag, or the like.

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Abstract

Provided are a distance measuring device and a distance measuring method which can easily distinguish a reflected signal from a desired tag from an unnecessary wave so as to improve the distance measuring accuracy even when IR-UWB is used for measuring a distance.  The method uses a reader ID indicated by a code string formed by P bits (P is a natural number) for identifying a base station and a tag ID indicated by a code string formed by Q bits (Q is a natural number) for identifying a radio terminal.  The method generates a unique word containing P pulses, each of which is ON/OFF-modulated depending on whether each of P bits indicating the reader ID is 1 or 0.  The method generates a frame containing 2 × M unique words and a burst containing Q frames.  The method further outputs a transmission signal containing a plurality of bursts.  A radio terminal ASK-modulates the transmission signal depending on whether each of the Q bits indicating the tag ID is 1 or 0.  The ASK-modulated signal is sampling-received at timings of different phases by 1/M (M is an integer not smaller than 1) of the transmission clock cycle.

Description

基地局装置及び測距方法Base station apparatus and ranging method
　本発明は、例えばＵＷＢ（Ultra Wide Band）無線等の無線技術を利用する無線測距システムにおける、無線端末との距離を測定する基地局装置及び測距方法に関する。 The present invention relates to a base station apparatus and a distance measuring method for measuring a distance from a wireless terminal in a wireless distance measuring system using a wireless technology such as UWB (Ultra Wide Band) wireless.
　無線測距システムでは、タグ等の無線端末と、リーダ等の基地局との間において無線通信を行い、無線端末の識別符号（識別ＩＤ）が多重された反射信号を基地局において受信し、その伝搬時間や方向等を検出する。これにより、無線端末と基地局の間の距離測定や、無線端末の位置測定を行う。このような無線測距システムでは、測定結果の信頼性や精度を高めるために、測定に用いる電波の特性を考慮してシステムを構成する必要がある。 In the wireless ranging system, wireless communication is performed between a wireless terminal such as a tag and a base station such as a reader, and a reflected signal in which an identification code (identification ID) of the wireless terminal is multiplexed is received at the base station. Propagation time and direction are detected. Thereby, the distance measurement between the wireless terminal and the base station and the position measurement of the wireless terminal are performed. In such a wireless ranging system, it is necessary to configure the system in consideration of characteristics of radio waves used for measurement in order to increase the reliability and accuracy of the measurement result.
　従来のＵＷＢ無線を用いた測距装置としては、特許文献１に示されているように、ＩＥＥＥ８０２．１５．４ａパケットを用いて、通信動作、測距（レンジング）動作及びパッシブレーダ動作（電波伝搬環境内の変化又は動きを検出すること、及び物体を追跡すること）を実行するものが知られている。この特許文献１で用いられる送信フォーマットを図１に示す。リーダは、電波伝搬環境内のタグの位置及び動きを、ＩＥＥＥ８０２．１５．４ａパケットに含まれる特定のプリアンブル構造を用いることによって検出する。 As a conventional ranging device using UWB radio, as shown in Patent Document 1, using IEEE802.15.4a packet, communication operation, ranging operation and ranging operation (radio wave propagation) Detecting changes or movement in the environment and tracking objects) are known. The transmission format used in this patent document 1 is shown in FIG. The reader detects the position and movement of the tag in the radio wave propagation environment by using a specific preamble structure included in the IEEE 802.15.4a packet.
　１つのプリンアブルを含むパケットの系列がリーダにより受信され、各パケット内のプリアンブルが逆拡散される。そして、基準マルチパスプロファイルが更新されると共に、現時点で受信されているパケットの「現在のマルチパスプロファイル」が得られる。この「現在のマルチパスプロファイル」を「基準マルチパスプロファイル」と比較することにより、その電波伝播環境内の物体が検出される。また、グラウンドスキャッタ（Ground Scatter）、すなわち、壁面等がない開放地において反射波として最も強い大地反射波が除去され、物体の位置、動き等が検出される。 A series of packets including one preamble is received by the reader, and the preamble in each packet is despread. Then, the reference multipath profile is updated, and the “current multipath profile” of the packet currently received is obtained. By comparing the “current multipath profile” with the “reference multipath profile”, an object in the radio wave propagation environment is detected. In addition, the ground scatter (Ground Scatter), that is, the strongest ground reflected wave as a reflected wave in an open ground without a wall surface or the like is removed, and the position, movement, etc. of the object are detected.
　また、この先行文献には、ＵＷＢ測距装置をパッシブレーダに応用するために、受信したパケットに後続する各パケット内のプリアンブルから、各パケットの「現在のマルチパスプロファイル」を求め、求めた各パケットの「現在のマルチパスプロファイル」を「基準マルチパスプロファイル」と比較する方式が示されている。 Further, in this prior document, in order to apply the UWB range finder to passive radar, the “current multipath profile” of each packet is obtained from the preamble in each packet subsequent to the received packet. A scheme for comparing a “current multipath profile” of a packet with a “reference multipath profile” is shown.
　従来の構成で仮定されているグラウンドスキャッタは、大地反射であるため、リーダが受信する信号の大多数を大地反射波が占める場合、リーダにおいて大地反射波は、パッシブタグからの反射信号よりも遅延量の大きい信号として検出される。また、リーダ、タグの高さが決定されている場合には、幾何学的な関係に基づいて、特定の時間領域の遅延プロファイルを容易に除去することができる。 Since the ground scatter assumed in the conventional configuration is ground reflection, when the ground reflected wave occupies the majority of the signal received by the reader, the ground reflected wave is delayed in the reader from the reflected signal from the passive tag. It is detected as a large signal. Further, when the heights of the reader and the tag are determined, a delay profile in a specific time domain can be easily removed based on the geometric relationship.
特開２００８―０２６３１０号公報JP 2008-026310 A
　しかしながら、現実には、パッシブ方式又はセミパッシブ方式では、ＩＤを検出すべきタグ（所望タグ）よりもリーダに近接している壁からの反射波が存在するような電波伝搬環境や、複数のタグが存在するような電波伝搬環境が想定されている。このような電波伝搬環境では、リーダに最も早く到着する先頭波を検出しても、検出した先頭波が、必ずしも所望のタグからの反射信号とは限らない。すなわち、先頭波が不要波である可能性がある。特に、測距にＩＲ―ＵＷＢを用いる場合には、不要波と、タグからの反射信号とが複数のパルスとして順次到来するため、先頭波を検出してもタグからの反射信号と不要波とを容易に識別することができない。 However, in reality, in the passive method or the semi-passive method, a radio wave propagation environment in which a reflected wave from a wall closer to the reader exists than a tag (desired tag) whose ID is to be detected, or a plurality of tags It is assumed that there is a radio wave propagation environment. In such a radio wave propagation environment, even if the head wave that arrives at the reader earliest is detected, the detected head wave is not necessarily a reflected signal from a desired tag. That is, the leading wave may be an unnecessary wave. In particular, when IR-UWB is used for distance measurement, an unnecessary wave and a reflected signal from the tag sequentially arrive as a plurality of pulses. Cannot be easily identified.
　本発明はかかる点に鑑みてなされたものであり、測距にＩＲ―ＵＷＢを用いた場合でも、所望のタグからの反射信号と不要波とを容易に識別することができ、測距の精度を向上させることができる基地局装置及び測距方法を提供することを目的とする。 The present invention has been made in view of such points, and even when IR-UWB is used for distance measurement, a reflected signal from a desired tag and an unnecessary wave can be easily identified, and accuracy of distance measurement is achieved. It is an object of the present invention to provide a base station apparatus and a distance measuring method that can improve performance.
　本発明の基地局装置は、基地局装置を識別するためのＰビット（Ｐは自然数）からなる符号列で示されるリーダＩＤと、無線端末を識別するためのＱビット（Ｑは自然数）からなる符号列で示されるタグＩＤとを用いる無線測距システムにおける基地局装置であって、Ｐ個のパルスを含み、前記リーダＩＤを示すＰビットの各々が１か０かによって各パルスがオンオフ変調されるユニークワードを生成し、前記ユニークワードを２×Ｍ個含むフレームを生成し、前記フレームをＱ個含むバーストを生成し、前記バーストを複数個含む送信信号を出力するパルス発生手段と、前記無線端末が前記タグＩＤを示すＱビットの各々が１か０かに基づいて前記送信信号を変調した信号を、送信クロック周期のＭ分の１（Ｍは１以上の整数）ずつ位相の異なるタイミングで、サンプリング受信する受信手段と、を具備する構成を採る。 The base station apparatus of the present invention comprises a reader ID indicated by a code string consisting of P bits (P is a natural number) for identifying the base station apparatus, and Q bits (Q is a natural number) for identifying the wireless terminal. A base station apparatus in a radio ranging system using a tag ID indicated by a code string, which includes P pulses, and each pulse is ON / OFF modulated depending on whether each of the P bits indicating the reader ID is 1 or 0 Generating a unique word, generating a frame including 2 × M unique words, generating a burst including Q frames, and outputting a transmission signal including a plurality of the bursts; and the radio The terminal modulates the signal obtained by modulating the transmission signal based on whether each of the Q bits indicating the tag ID is 1 or 0 by 1 / M of the transmission clock cycle (M is an integer of 1 or more). At different timings, a configuration comprising a receiving means for sampling receiver, the.
　本発明の測距方法は、基地局装置を識別するためのＰビット（Ｐは自然数）からなる符号列で示されるリーダＩＤと、無線端末を識別するためのＱビット（Ｑは自然数）からなる符号列で示されるタグＩＤとを用いる無線測距システムの前記基地局装置における測距方法であって、Ｐ個のパルスを含み、前記リーダＩＤを示すＰビットの各々が１か０かによって各パルスがオンオフ変調されるユニークワードを生成し、前記ユニークワードを２×Ｍ個含むフレームを生成し、前記フレームをＱ個含むバーストを生成し、前記バーストを複数個含む送信信号を出力し、前記無線端末が前記タグＩＤを示すＱビットの各々が１か０かに基づいて前記送信信号をＡＳＫ変調した信号を、送信クロック周期のＭ分の１（Ｍは１以上の整数）ずつ位相の異なるタイミングで、サンプリング受信するようにした。 The distance measuring method of the present invention comprises a reader ID indicated by a code string consisting of P bits (P is a natural number) for identifying a base station apparatus, and Q bits (Q is a natural number) for identifying a wireless terminal. A ranging method in the base station apparatus of a radio ranging system using a tag ID indicated by a code string, which includes P pulses, and each of the P bits indicating the reader ID is 1 or 0. Generating a unique word in which pulses are modulated on and off, generating a frame including 2 × M unique words, generating a burst including Q frames, and outputting a transmission signal including a plurality of the bursts; A wireless terminal phase-shifts a signal obtained by ASK-modulating the transmission signal based on whether each Q bit indicating the tag ID is 1 or 0 by 1 / M (M is an integer of 1 or more) of the transmission clock period. At different times and to sample received.
　本発明によれば、測距にＩＲ―ＵＷＢを用いた場合でも、所望のタグからの反射信号と不要波とを容易に識別することができ、測距の精度を向上させることができる。 According to the present invention, even when IR-UWB is used for distance measurement, a reflected signal from an intended tag and an unnecessary wave can be easily identified, and the accuracy of distance measurement can be improved.
特許文献１に記載の送信フォーマットを示す図The figure which shows the transmission format of patent document 1 電波伝搬環境を示す図Diagram showing radio wave propagation environment 本発明の実施の形態１に係る測距装置の構成を示すブロック図1 is a block diagram showing the configuration of a distance measuring device according to Embodiment 1 of the present invention. 図３に示したリーダが送信する送信フォーマットの一例を示す図The figure which shows an example of the transmission format which the reader | leader shown in FIG. 3 transmits タグの送信フォーマットの一例を示す図Diagram showing an example of tag transmission format バースト列と遅延プロファイルの関係を示す図Diagram showing the relationship between burst sequence and delay profile 位相シフトサンプリングの動作を示す図Diagram showing operation of phase shift sampling 本発明の実施の形態２に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 2 of this invention. 本発明の実施の形態２に係るリーダ及びタグの機能的構成を示すブロック図The block diagram which shows the functional structure of the reader and tag which concern on Embodiment 2 of this invention 本発明の実施の形態３に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 3 of this invention. 本発明の実施の形態４に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 4 of this invention. 本発明の実施の形態５に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 5 of this invention. 本発明の実施の形態６に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 6 of this invention. 本発明の実施の形態７に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 7 of this invention. 本発明の実施の形態８に係る無線測距システムの全体構成を示す図The figure which shows the whole structure of the radio | wireless ranging system which concerns on Embodiment 8 of this invention.
　以下、本発明の実施の形態について、図面を参照して詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
　図２（ａ）は、電波伝搬環境の一例を示す概略図である。基地局であるリーダ２０１から送出された電波は、所望タグ（ＴＡＧ１）２０２においてそのタグ自身を識別するためのタグＩＤが付加された後、再びリーダで反射信号として受信されることが望まれる。しかしながら、実際の電波伝搬環境には、所望タグの他にも数々の反射体が存在する。反射体としては、例えば、他のタグ（ＴＡＧ２）２０３、壁面２０４、リーダの近くに存在する反射物２０５、リーダから遠くに存在する反射物２０６などがある。これらの反射体からの反射波は、リーダ２０１で観測される遅延プロファイル上においては、それぞれ異なる遅延プロファイルのピークとして検出される。 FIG. 2A is a schematic diagram showing an example of a radio wave propagation environment. It is desirable that the radio wave transmitted from the reader 201 as the base station is received again as a reflected signal by the reader after the tag ID for identifying the tag itself is added in the desired tag (TAG1) 202. However, in an actual radio wave propagation environment, there are numerous reflectors in addition to the desired tag. Examples of the reflector include another tag (TAG2) 203, a wall surface 204, a reflector 205 that exists near the reader, and a reflector 206 that exists far from the reader. Reflected waves from these reflectors are detected as different delay profile peaks on the delay profile observed by the reader 201.
　リーダ２０１が送信する送信信号は、図２（ｂ）に示すように周期的に送出されるパルス列２１０を有する。これに対して、リーダ２０１が受信した信号の遅延プロファイル上では、図２（ｃ）に示すように、近接した反射物２０５の反射波を示すピーク２１１、ＴＡＧ１からの反射波を示すピーク２１２、遠方の反射物２０６の反射波を示すピーク２１３、ＴＡＧ２からの反射波を示すピーク２１４が検出される。図２（ｃ）は一例であるが、この図に示すように、最もレベルの大きい先頭波のピーク２１１が、所望タグからの反射波（ＴＡＧ１のタグＩＤが付加された信号）ではないことがありうる。 The transmission signal transmitted by the reader 201 has a pulse train 210 periodically transmitted as shown in FIG. On the other hand, on the delay profile of the signal received by the reader 201, as shown in FIG. 2C, the peak 211 indicating the reflected wave of the adjacent reflector 205, the peak 212 indicating the reflected wave from TAG1, A peak 213 indicating a reflected wave from the distant reflector 206 and a peak 214 indicating a reflected wave from TAG2 are detected. Although FIG. 2C is an example, as shown in this figure, the peak 211 of the leading wave having the highest level is not a reflected wave from the desired tag (a signal to which the tag ID of TAG1 is added). It is possible.
　図２（ｃ）の場合は、先頭波２１１は、近接した反射物２０５からの反射波であるため、この信号を除去する必要がある。また、タグも複数あるため、所望のタグＩＤが付加された反射波（ピーク２１２）と他のタグＩＤが付加された反射波（ピーク２１４）とは、これらの遅延時間を用いて分離する必要がある。 In the case of FIG. 2 (c), the leading wave 211 is a reflected wave from the adjacent reflector 205, and thus this signal needs to be removed. Since there are a plurality of tags, the reflected wave (peak 212) to which a desired tag ID is added and the reflected wave (peak 214) to which another tag ID is added need to be separated using these delay times. There is.
　図３は、本発明の実施の形態に係る測距装置の構成を示すブロック図である。図３において、タグ３００は、タグ受信アンテナ３０１、タグ送信アンテナ３０２を有する。なお、これらのアンテナは、分配器やサーキュレータ等を用いて共用化してもよい。リーダ３１０から送出された送信信号、例えば、ＩＲ－ＵＷＢパルス列信号は、タグ受信アンテナ３０１によって受信される。 FIG. 3 is a block diagram showing the configuration of the distance measuring apparatus according to the embodiment of the present invention. In FIG. 3, the tag 300 includes a tag reception antenna 301 and a tag transmission antenna 302. Note that these antennas may be shared by using a distributor, a circulator, or the like. A transmission signal transmitted from the reader 310, for example, an IR-UWB pulse train signal is received by the tag receiving antenna 301.
　まず、タグ３００の動作について説明する。タグ３００のタグＩＤ付加部３０４は、各タグに固有の識別ＩＤとして割り当てられたタグＩＤをメモリや配線論理により保持している。ＡＳＫ変調部３０３は、タグＩＤ付加部３０４に保持されているタグＩＤを読み出し、タグＩＤを示す符号列（ビット“０”とビット“１”からなる符号列）を用いて、リーダから受信したパルス列信号に対して、ＡＳＫ変調（Amplitude Shift Keying Modulation）をかける。タグ３００は、ＡＳＫ変調により得られた信号を、タグ送信アンテナ３０２から送出する。このＡＳＫ変調部３０３の動作は、一般的なパッシブタグやセミパッシブタグが、リーダからの連続搬送波に対してＡＳＫ変調をかけることにより、自身のタグＩＤをリーダへ返送する動作に類似している。 First, the operation of the tag 300 will be described. A tag ID adding unit 304 of the tag 300 holds a tag ID assigned as an identification ID unique to each tag using a memory or wiring logic. The ASK modulation unit 303 reads the tag ID held in the tag ID addition unit 304 and receives the tag ID from the reader using a code sequence (a code sequence including bit “0” and bit “1”) indicating the tag ID. ASK modulation (Amplitude Shift Keying Modulation) is applied to the pulse train signal. The tag 300 transmits a signal obtained by ASK modulation from the tag transmission antenna 302. The operation of the ASK modulation unit 303 is similar to the operation of a general passive tag or semi-passive tag returning its tag ID to the reader by applying ASK modulation to the continuous carrier wave from the reader. .
　本実施の形態においては、タグ３００は、リーダ３１０から送信されたパルス列信号に対して、タグＩＤを用いて下記のようにＡＳＫ変調を行う。具体的には、タグＩＤの符号列を構成するビット“１”に対しては、リーダから送信されたパルス列をそのまま返送する。また、タグＩＤの符号列を構成するビット“０”に対しては、リーダから送信されたパルス列を返送しない。このような、パルス列を返送するか否かの切り替えは、例えば、下記の方法で実現できる。パッシブ方式の場合には、ＡＳＫ変調部３０３がタグ受信アンテナ端を不整合、整合で切り替えたり、またはタグ受信アンテナ、タグ送信アンテナ間を接続又は終端したりすることにより実現できる。また、セミパッシブ方式の場合には、ＡＳＫ変調部３０３が低雑音増幅回路（ＬＮＡ：Low Noise Amplifier）又はパワーアンプの電源をオン、オフすることにより実現できる。 In the present embodiment, the tag 300 performs ASK modulation on the pulse train signal transmitted from the reader 310 using the tag ID as follows. More specifically, the pulse train transmitted from the reader is returned as it is to the bit “1” constituting the code sequence of the tag ID. In addition, the pulse train transmitted from the reader is not returned to the bit “0” constituting the code sequence of the tag ID. Such switching of whether or not to return a pulse train can be realized by the following method, for example. In the case of the passive method, the ASK modulation unit 303 can be realized by switching the tag receiving antenna end by mismatch or matching, or by connecting or terminating between the tag receiving antenna and the tag transmitting antenna. In the case of the semi-passive method, the ASK modulation unit 303 can be realized by turning on / off a low noise amplifier circuit (LNA: Low / Noise / Amplifier) or a power amplifier.
　次に、リーダ３１０の動作について説明する。リーダ３１０のリーダＩＤ保持部３１３は、各リーダに固有の識別ＩＤとして割り当てられたリーダＩＤをメモリや配線論理により保持している。送信パルス発生部３１２は、リーダＩＤ保持部３１３に保持されているリーダＩＤを読み出し、リーダＩＤの符号列に基づいて、ＯＯＫ（On-Off-Keying）変調を行う。これにより生成されたリーダＩＤに対応するパルス列が、リーダ送信アンテナ３１１から、送信信号として周期的に送信される。 Next, the operation of the reader 310 will be described. A reader ID holding unit 313 of the reader 310 holds a reader ID assigned as an identification ID unique to each reader using a memory or wiring logic. The transmission pulse generator 312 reads the reader ID held in the reader ID holding unit 313 and performs OOK (On-Off-Keying) modulation based on the code string of the reader ID. A pulse train corresponding to the reader ID thus generated is periodically transmitted as a transmission signal from the reader transmission antenna 311.
　リーダ受信アンテナ３１４は、タグ３００から返送され、タグＩＤが付加された反射信号（パルス列を含む）を受信する。リーダＩＤ相関演算部３１５は、リーダ受信アンテナ３１４によって受信された反射信号と、リーダＩＤ保持部３１３から読み出したリーダＩＤとのスライディング自己相関処理を行い、各周期に対応する複数の遅延プロファイルを生成する。生成された遅延プロファイルはピーク検出部３１６に出力される。 The reader receiving antenna 314 receives a reflected signal (including a pulse train) returned from the tag 300 and added with a tag ID. The reader ID correlation calculation unit 315 performs a sliding autocorrelation process between the reflected signal received by the reader receiving antenna 314 and the reader ID read from the reader ID holding unit 313, and generates a plurality of delay profiles corresponding to each cycle. To do. The generated delay profile is output to the peak detector 316.
　ピーク検出部３１６は、リーダＩＤ相関演算部３１５から出力された複数の遅延プロファイルに対してピークサーチを行い、不要波である反射波や、複数のタグから送出された反射信号を抽出する。抽出された反射波及び複数のタグから送出された反射信号は、タグＩＤ相関演算部３１８に出力される。 The peak detection unit 316 performs a peak search on the plurality of delay profiles output from the reader ID correlation calculation unit 315, and extracts reflected waves that are unnecessary waves and reflected signals transmitted from a plurality of tags. The extracted reflected wave and the reflected signal transmitted from the plurality of tags are output to the tag ID correlation calculation unit 318.
　タグＩＤ保持部３１７は、リーダ３１０と予め関連付けられた、複数のタグＩＤをメモリや配線論理により保持している。タグＩＤ相関演算部３１８は、タグＩＤ保持部３１７に保持されている複数のタグＩＤの中から所望のタグＩＤを読み出し、読み出したタグＩＤと、ピーク検出部３１６から出力された信号との相関処理を行う。この相関処理により、タグＩＤ相関演算部３１８は、所望のタグＩＤと一致する遅延プロファイルを特定し、特定の遅延時間のピークの組を検出する。 The tag ID holding unit 317 holds a plurality of tag IDs associated with the reader 310 in advance using a memory or wiring logic. The tag ID correlation calculation unit 318 reads a desired tag ID from a plurality of tag IDs held in the tag ID holding unit 317, and correlates the read tag ID with the signal output from the peak detection unit 316. Process. By this correlation processing, the tag ID correlation calculation unit 318 identifies a delay profile that matches the desired tag ID, and detects a set of peaks of a specific delay time.
　先頭波検出部３１９は、所望のタグＩＤに対して、有意な相関のある遅延プロファイルを持つピークが複数個得られた場合、最も遅延時間の少ない遅延プロファイルのピーク（タグＩＤの先頭波）を検出し、検出されたピークを遅延時間測定部３２０に出力する。 When a plurality of peaks having a significantly correlated delay profile are obtained for a desired tag ID, the leading wave detection unit 319 selects the peak of the delay profile with the shortest delay time (the leading wave of the tag ID). The detected peak is output to the delay time measuring unit 320.
　遅延時間測定部３２０は、タグへの送信信号を送信した基準タイミングと、タグからの反射信号を受信したタイミングとを比較し、遅延時間、すなわち、リーダ３１０から送信された信号がタグ３００を介して再びリーダ３１０に受信されるまでに要した時間を抽出する。抽出された遅延時間は距離算出部３２１に出力される。 The delay time measurement unit 320 compares the reference timing at which the transmission signal to the tag is transmitted with the timing at which the reflected signal from the tag is received, and the delay time, that is, the signal transmitted from the reader 310 is transmitted via the tag 300. Then, the time required until it is received again by the reader 310 is extracted. The extracted delay time is output to the distance calculation unit 321.
　距離算出部３２１は、遅延時間測定部３２０から出力された遅延時間を用いて、タグとリーダとの距離を算出する。 The distance calculation unit 321 calculates the distance between the tag and the reader using the delay time output from the delay time measurement unit 320.
　図４は、図３に示したリーダ３１０が送信する送信フォーマットの一例を示す図である。図４（ａ）は、リーダ送信アンテナ３１１から送信されるパルス列を示す。これは、送信パルス発生部３１２が、リーダＩＤ保持部３１３に保持されているリーダＩＤの符号列に基づいてＯＯＫ変調を行うことにより生成したパルス列である。これにより、リーダＩＤに対応するパルス列が周期的に送信される。 FIG. 4 is a diagram showing an example of a transmission format transmitted by the reader 310 shown in FIG. FIG. 4A shows a pulse train transmitted from the reader transmission antenna 311. This is a pulse train generated by the transmission pulse generator 312 performing OOK modulation based on the code sequence of the reader ID held in the reader ID holder 313. Thereby, a pulse train corresponding to the reader ID is periodically transmitted.
　図４（ａ）では、リーダＩＤが１２８個のパルスを用いて表される場合を仮定しているが、複数のリーダＩＤを一意に区別できるものであればパルス数には特に限定はない。パルス数の決定の基準は、システムに収容されるリーダ数に対応する。また、リーダＩＤとして信号処理利得を得る必要がある場合には、自己相関の高いＰＮ符号やＧＯＬＤ符号が用いられる。ここでは、リーダＩＤを表現する１２８パルスの系列をユニークワード（以下、「ＵＷ」という）と呼ぶ。図４（ｂ）に示すように、ＵＷは必ずｎ個（ｎは２以上）が一セットになって処理される。ここでは、この一セットをフレームと呼ぶ。 In FIG. 4A, it is assumed that the reader ID is represented using 128 pulses. However, the number of pulses is not particularly limited as long as a plurality of reader IDs can be uniquely distinguished. The criterion for determining the number of pulses corresponds to the number of readers accommodated in the system. In addition, when it is necessary to obtain a signal processing gain as the reader ID, a PN code or GOLD code with high autocorrelation is used. Here, a series of 128 pulses representing the reader ID is referred to as a unique word (hereinafter referred to as “UW”). As shown in FIG. 4B, n UWs (n is 2 or more) are always processed as one set. Here, this one set is called a frame.
　以下、１フレーム内のｎ個（本実施の形態では１６個）のＵＷが一セットになって処理される理由について説明する。リーダとタグとの間では、それぞれの動作の基準となる原振が位相同期しておらず、すなわち、非同期である。また若干の周波数誤差が生じる。従って、リーダからの送信信号を受信したタグは、リーダからの送信信号に含まれるＵＷと、反射信号に付加するタグＩＤとを同期した状態で送出するとは限らない。 Hereinafter, the reason why n (16 in this embodiment) UWs in one frame are processed as one set will be described. Between the reader and the tag, the original oscillation that is the basis of each operation is not phase-synchronized, that is, asynchronous. In addition, a slight frequency error occurs. Therefore, the tag that has received the transmission signal from the reader does not always send out the UW included in the transmission signal from the reader and the tag ID added to the reflected signal in a synchronized state.
　また、ＵＷＢパルス列のパルス幅は送信クロック周期と同じであり、オーバーサンプリングすることができない。したがって、タグからの反射波を確実にサンプリングするためには、受信サンプリングタイミングを送信クロックの周期に対して位相シフトしてから、反射波をサンプリングすることが好ましい。特に、ＩＲ－ＵＷＢにおいて、パルスの周波数帯域幅が制限されている場合には、受信信号の波形が方形波に比較して三角波のような形状となるため、受信信号を位相シフトしてサンプリングすることは有効である。 Also, the pulse width of the UWB pulse train is the same as the transmission clock cycle, and oversampling cannot be performed. Therefore, in order to reliably sample the reflected wave from the tag, it is preferable to sample the reflected wave after phase shifting the reception sampling timing with respect to the cycle of the transmission clock. In particular, in IR-UWB, when the frequency bandwidth of a pulse is limited, the waveform of the received signal is shaped like a triangular wave as compared to a square wave, so the received signal is phase shifted and sampled. It is effective.
　これを実現するためには、リーダが、位相シフトされた受信信号をサンプリングできるような構成にすればよい。つまり、送信クロック周期の整数分の１ずつ、受信信号を位相シフトさせてサンプリングができるように、ｎ個のＵＷからなるセットを整数回送出する。例えば、位相シフト量をクロック周期の８分の１にする場合には、リーダ及びタグの非同期に対応する２回と、位相シフトに対応する８回の乗算として、ｎ＝２×８＝１６個のＵＷが１セットとして送信される。この１セットの連続信号が、図４（ｃ）のフレームである。 In order to realize this, the reader may be configured to be able to sample the phase-shifted received signal. That is, a set of n UWs is sent an integer number of times so that the received signal can be phase shifted by 1 / integer of the transmission clock period. For example, when the phase shift amount is set to 1/8 of the clock period, n = 2 × 8 = 16 multiplications are performed twice, corresponding to asynchronous reader / tag and 8 times corresponding to phase shift. Are transmitted as a set. This set of continuous signals is the frame of FIG.
　タグは、このフレーム１つに対して、１ビット分のＡＳＫ変調を行う。例えば、１２８ビットのタグＩＤをタグが送信する場合には、１２８フレームからなるパルス列の連続信号を送信することが必要となる。図４（ｄ）は、タグＩＤを送信するのに必要な１２８フレームを、１つのバーストとして表したものである。タグは、１つのバーストを用いてタグＩＤを１回送出することができる。なお、１つのバーストを構成するフレーム数は、タグＩＤを構成する複数のビット全てを送信することができれば、１２８に限定されない。 The tag performs 1-bit ASK modulation for one frame. For example, when a tag transmits a 128-bit tag ID, it is necessary to transmit a continuous signal of a pulse train composed of 128 frames. FIG. 4D shows 128 frames necessary for transmitting the tag ID as one burst. A tag can send a tag ID once using one burst. The number of frames constituting one burst is not limited to 128 as long as all the plurality of bits constituting the tag ID can be transmitted.
　このようにして、リーダは、１つのバースト当たり、１２８パルス×１６ＵＷ×１２８フレームのパルス列を繰り返し送信し、このバーストを用いてタグＩＤの処理を行うことができる。送信クロックは時間基準となるためいつも一定周期であるが、受信動作は位相シフトクロックによりサンプリングされるため、周波数は送信クロックと受信クロックとで共通であるが、それぞれのクロックのタイミング（位相）は異なる。 In this way, the reader can repeatedly transmit a pulse train of 128 pulses × 16 UW × 128 frames per burst, and process the tag ID using this burst. Since the transmission clock is a time reference, it is always a fixed period, but because the reception operation is sampled by the phase shift clock, the frequency is the same for both the transmission clock and the reception clock, but the timing (phase) of each clock is Different.
　図５は、タグの送信フォーマットの一例を示す図である。図５においては、説明の便宜上、リーダにおける受信サンプリングの位相シフトを行わない場合、すなわち、１フレームが２ＵＷの場合を示している。上述したように、タグとリーダとは非同期であるため、タグがタグＩＤを送信するタイミングは１つに決定されない。 FIG. 5 is a diagram showing an example of a tag transmission format. For convenience of explanation, FIG. 5 shows a case where phase shift of reception sampling in the reader is not performed, that is, a case where one frame is 2 UW. As described above, since the tag and the reader are asynchronous, the timing at which the tag transmits the tag ID is not determined as one.
　図５の例では、ＵＷ５０１のタイミングで、スタートビットに相当するタグＩＤ符号“０”（５０４）が、タグ３００により付加され、リーダ３１０へ反射信号として送信されたとしている。タグＩＤを構成する符号列に含まれる１ビットは、１フレーム長、すなわち、ここでは、２ＵＷに相当する長さで送信される。したがって、リーダが送信するフレームの送信タイミングと、タグが送信するタグＩＤの送信タイミングがずれている場合でも、フレーム内の２個のＵＷのうち、前のＵＷか後のＵＷの一方のタイミングは、タグＩＤ符号（ビット“０”またはビット“１”）の符号変化点にかかってしまう。ところが、他方のタイミングのＵＷは、符号変化点にかからないため、タグＩＤを構成する符号列に含まれるビット“１”又はビット“０”を示す信号が、１つのＵＷにおいてＡＳＫ変調されて送信される。従って、１つのＵＷ区間でタグＩＤの変化点がない場合は、リーダとタグとが同期しているとみなされてタグＩＤ符号が送信され、リーダでは、ＵＷに同期したタグＩＤ符号が送信されたと判断し、このＵＷに対応するタグＩＤ符号を検出する。一方、１つのＵＷ内にタグＩＤ符号の変化点がある場合には、同期しないＵＷと見なし、リーダでは、このＵＷをタグＩＤ符号の検出に用いないこととする。 In the example of FIG. 5, it is assumed that the tag ID code “0” (504) corresponding to the start bit is added by the tag 300 and transmitted to the reader 310 as a reflected signal at the timing of UW501. One bit included in the code string constituting the tag ID is transmitted with one frame length, that is, here, a length corresponding to 2 UW. Therefore, even when the transmission timing of the frame transmitted by the reader is different from the transmission timing of the tag ID transmitted by the tag, the timing of one of the previous UW and the subsequent UW among the two UWs in the frame is , The code change point of the tag ID code (bit “0” or bit “1”) is applied. However, since the UW at the other timing does not reach the code change point, the signal indicating the bit “1” or the bit “0” included in the code string constituting the tag ID is ASK-modulated and transmitted in one UW. The Therefore, when there is no tag ID change point in one UW section, it is assumed that the reader and the tag are synchronized, and the tag ID code is transmitted. The reader transmits the tag ID code synchronized with UW. The tag ID code corresponding to this UW is detected. On the other hand, if there is a change point of the tag ID code in one UW, it is regarded as an unsynchronized UW, and the reader does not use this UW for detection of the tag ID code.
　図５の場合、タグＩＤの送信タイミングは、１フレーム内の後半のＵＷ５０１に同期しているとみなすことができる。したがって、リーダは、このＵＷに対して相関処理を行えば、タグＩＤを構成するタグＩＤ符号を検出することができる。以下、タグＩＤ符号“１”（５０５）、タグＩＤ符号“１”（５０６）に関しても同様に、タグＩＤの送信タイミングが、各フレーム内の後半のＵＷ５０２、５０３に同期しているとみなされる。なお、タグのＩＤ符号が立ち上がる（タグＩＤ符号が“０”から“１”になる）タイミングによっては、前半のＵＷに同期したとみなされるタグＩＤが送信される場合もある。この図５に対応するリーダの受信処理は、リーダＩＤ相関演算部１１６が、ＵＷに対して相関処理を行い、ピーク検出部１１６が前半のＵＷに同期しているとみなすか、後半のＵＷに同期しているとみなすかを判定する。 In the case of FIG. 5, it can be considered that the transmission timing of the tag ID is synchronized with the UW 501 in the latter half of one frame. Therefore, the reader can detect the tag ID code constituting the tag ID by performing correlation processing on this UW. Hereinafter, similarly, regarding the tag ID code “1” (505) and the tag ID code “1” (506), it is considered that the transmission timing of the tag ID is synchronized with the UWs 502 and 503 in the latter half of each frame. . Depending on the timing at which the tag ID code rises (the tag ID code changes from “0” to “1”), a tag ID that is considered to be synchronized with the first half UW may be transmitted. The reader reception processing corresponding to FIG. 5 is performed by determining whether the reader ID correlation calculation unit 116 performs correlation processing on the UW and the peak detection unit 116 is synchronized with the first half UW, or the second half UW. Determine if it is considered synchronized.
　図６は、バースト列と遅延プロファイルの関係を示している。図６（ａ）に示しているように、リーダにおいては、近傍反射波、タグＩＤ送信波、遠方反射波、タグＩＤの反射波が壁等によって反射した反射波の遅延プロファイルが観測されていると仮定する。 FIG. 6 shows the relationship between burst sequences and delay profiles. As shown in FIG. 6 (a), in the reader, a delay profile of a reflected wave in which a reflected wave near, a tag ID transmission wave, a far reflection wave, and a tag ID reflection wave is reflected by a wall or the like is observed. Assume that
　図６（ｂ）において、６０１は近傍反射波のバースト列検出結果、６０２はタグＩＤ送信波のバースト列検出結果、６０３は遠方反射波のバースト列検出結果、６０４はタグＩＤ反射波のバースト列検出結果である。６０１及び６０３は、反射物からの反射波であるため、バースト列に対して信号の振幅変動が起こらない。これに対して、６０２及び６０４はタグから送信されたＩＤがＡＳＫ変調により付加された信号であり、フレーム単位でタグＩＤに対応する振幅変化が見られ、バーコード状の検出結果が得られる。この結果に対して、バースト方向にタグＩＤ相関演算部３１８がタグＩＤとの相関を取り、相関が得られればその検出結果６０２、６０４を候補バーストとする。次に、先頭波検出部３１９は、候補バーストのうち、遅延プロファイルの先頭波を６０２として検出する。遅延時間測定部３２０は、遅延プロファイル上の送信基準タイミングと先頭波検出部３１９の出力である所望のタグＩＤの検出時間を計算して、遅延時間を測定する。 In FIG. 6B, reference numeral 601 denotes a burst string detection result of a near reflection wave, 602 denotes a burst string detection result of a tag ID transmission wave, 603 denotes a burst string detection result of a far reflection wave, and 604 denotes a burst string of a tag ID reflection wave. It is a detection result. Since 601 and 603 are reflected waves from the reflector, signal amplitude fluctuation does not occur with respect to the burst train. On the other hand, reference numerals 602 and 604 are signals to which IDs transmitted from the tags are added by ASK modulation. Amplitude changes corresponding to the tag IDs are seen on a frame basis, and bar-code detection results are obtained. In response to this result, the tag ID correlation calculation unit 318 correlates with the tag ID in the burst direction, and if a correlation is obtained, the detection results 602 and 604 are set as candidate bursts. Next, the leading wave detection unit 319 detects the leading wave of the delay profile as 602 among the candidate bursts. The delay time measurement unit 320 calculates the transmission reference timing on the delay profile and the detection time of the desired tag ID that is the output of the leading wave detection unit 319, and measures the delay time.
　図７は、位相シフトサンプリングの動作を示す図である。図７において、７０１はリーダからの送信信号の波形を示し、７０２はリーダが受信する信号の波形を示す。７０２は、ＵＷＢの帯域制限により信号の波形は７０１と異なり、信号振幅も異なる。図７において、位相シフト１から８はサンプリングタイミングを示しているが、このタイミングは受信するたびに異なる。このため、本実施の形態においては、リーダＩＤ相関演算部３１５が自リーダとの信号相関をとる前に８位相成分を全て加算して電力を増加させる。ここでは、８分の１ずつ位相シフトさせたタイミングでサンプリングしているが、８分の１に限られない。 FIG. 7 is a diagram showing the phase shift sampling operation. In FIG. 7, reference numeral 701 denotes a waveform of a transmission signal from the reader, and reference numeral 702 denotes a waveform of a signal received by the reader. The signal waveform 702 is different from the signal waveform 701 and has a different signal amplitude due to the UWB band limitation. In FIG. 7, phase shifts 1 to 8 indicate the sampling timing, but this timing is different every time it is received. For this reason, in this embodiment, before the reader ID correlation calculation unit 315 obtains signal correlation with its own reader, all eight phase components are added to increase the power. Here, the sampling is performed at the timing of phase shift by 1/8, but is not limited to 1/8.
　このように実施の形態１によれば、基地局を識別するためのＰビット（Ｐは自然数）からなる符号列で示されるリーダＩＤと、無線端末を識別するためのＱビット（Ｑは自然数）からなる符号列で示されるタグＩＤとを用い、Ｐ個のパルスを含み、リーダＩＤを示すＰビットの各々が１か０かによって各パルスがオンオフ変調されるユニークワードを生成し、ユニークワードを２×Ｍ個含むフレームを生成し、フレームをＱ個含むバーストを生成し、バーストを複数個含む送信信号を出力し、無線端末が前記タグＩＤを示すＱビットの各々が１か０かに基づいて送信信号をＡＳＫ変調した信号を、送信クロック周期のＭ分の１（Ｍは１以上の整数）ずつ位相の異なるタイミングで、サンプリング受信することにより、測距にＵＷＢ信号を用いた場合でも、リーダは、簡易な構成で、所望タグからの反射信号と不要波とを精度よく識別することができ、測距の精度を向上させることができる。 As described above, according to the first embodiment, the reader ID indicated by the code string composed of the P bits (P is a natural number) for identifying the base station and the Q bits (Q is a natural number) for identifying the wireless terminal. A unique word in which each pulse is on / off modulated depending on whether each of the P bits indicating the reader ID is 1 or 0 is generated using the tag ID indicated by the code string consisting of A frame including 2 × M frames is generated, a burst including Q frames is generated, a transmission signal including a plurality of bursts is output, and the wireless terminal is based on whether each of the Q bits indicating the tag ID is 1 or 0 The UWB signal is used for ranging by sampling and receiving a signal obtained by ASK modulation of the transmission signal at a timing with a phase difference of 1 / M (M is an integer of 1 or more) of the transmission clock period. Even if the reader is a simple structure, the reflected signal and the unnecessary wave from the desired tag can be identified accurately, it is possible to improve the accuracy of the distance measurement.
　（実施の形態２）
　図８は、本発明の実施の形態２に係る無線測距システムの全体構成を示す図である。無線測距システムは、リーダ８００、第１のタグ８０１、第２のタグ８０２を有して構成される。第１のタグ８０１は、人間８５０が身に着ける名札８１０の表面に搭載され、第２のタグ８０２は、この名札８１０に接続された輪状の首かけひも８０３の、前記名札との接続位置とは異なる位置に装着されている。第２のタグ８０２は、例えば、首かけひも８０３の中間部分に装着されている。人間８５０が名札８１０を身に着ける際は、首かけひも８０３を首にかけて名札８１０を胸の前にぶら下げた状態とすると、第２のタグ８０２が首の後部分に位置するため、第１のタグ８０１が人体の前方に向かって配置され、第２のタグ８０２が人体の後方に向かって配置されることになる。 (Embodiment 2)
FIG. 8 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 2 of the present invention. The wireless ranging system includes a reader 800, a first tag 801, and a second tag 802. The first tag 801 is mounted on the surface of the name tag 810 worn by the human 850, and the second tag 802 is the position of the ring-shaped neck strap 803 connected to the name tag 810 and the position of the name tag. Are mounted in different positions. For example, the second tag 802 is attached to an intermediate portion of the neck strap 803. When the person 850 wears the name tag 810, if the name tag 810 is hung in front of the chest with the neck strap 803 on the neck, the second tag 802 is located at the rear part of the neck. The tag 801 is disposed toward the front of the human body, and the second tag 802 is disposed toward the rear of the human body.
　図９は、本発明の実施の形態２に係るリーダ及びタグの構成を示すブロック図である。ここで、リーダ及びタグによる無線測距システムの構成及び動作について説明する。リーダ８００は、ＵＷＢを用いる無線装置であり、測距方式はアクティブ方式、パッシブ方式、セミパッシブ方式のいずれも適用可能である。図９では、一例としてセミパッシブ方式の構成を示している。 FIG. 9 is a block diagram showing the configuration of the reader and tag according to Embodiment 2 of the present invention. Here, the configuration and operation of a wireless ranging system using a reader and a tag will be described. The reader 800 is a wireless device using UWB, and any of a ranging method, an active method, a passive method, and a semi-passive method can be applied. FIG. 9 shows a semi-passive configuration as an example.
　タグとリーダを用いた、タグ－リーダ間の距離測定は、タグとリーダとの間で送受信される測定用信号の伝搬時間を用いて行われる。測定用信号の伝搬時間を算出し、その伝搬時間に電波の伝搬速度を積算すれば、タグとリーダ間の距離が求められる。パッシブ方式及びセミパッシブ方式のタグにおいてはいずれも、リーダからの送信電波を反射または増幅して再放射し、タグの識別ＩＤとしてタグＩＤを送信する。これにより、リーダ内部においてカウントされる絶対基準時間に基づいて、タグ－リーダ間を往復した測定用信号の往復時間を算出することができる。 The distance measurement between the tag and the reader using the tag and the reader is performed using the propagation time of the measurement signal transmitted and received between the tag and the reader. If the propagation time of the measurement signal is calculated and the propagation speed of the radio wave is added to the propagation time, the distance between the tag and the reader can be obtained. In both passive and semi-passive tags, the transmission radio wave from the reader is reflected or amplified and re-radiated, and the tag ID is transmitted as the tag identification ID. Thereby, based on the absolute reference time counted inside the reader, it is possible to calculate the round-trip time of the measurement signal that reciprocates between the tag and the reader.
　図９において、タグ９００は、受信アンテナ９０１、送信アンテナ９０２、タグＩＤ付加部９０３を備えている。また、リーダ９１０は、送信アンテナ９１１、送信パルス発生部９１２、タイミング信号出力部９１３、受信アンテナ９１４、パルス検出部９１５、タグＩＤ検出部９１８、遅延時間測定部９１６、距離算出部９１７を備えている。 9, the tag 900 includes a receiving antenna 901, a transmitting antenna 902, and a tag ID adding unit 903. The reader 910 includes a transmission antenna 911, a transmission pulse generation unit 912, a timing signal output unit 913, a reception antenna 914, a pulse detection unit 915, a tag ID detection unit 918, a delay time measurement unit 916, and a distance calculation unit 917. Yes.
　リーダ９１０は、タイミング信号出力部９１３において、基準となるタイミング信号を生成して出力し、送信パルス発生部９１２において、タイミング信号に応じて測定用のＵＷＢパルスを発生して送信アンテナ９１１から空間に放射する。 The reader 910 generates and outputs a reference timing signal at the timing signal output unit 913, and generates a UWB pulse for measurement according to the timing signal at the transmission pulse generation unit 912, and transmits the UWB pulse from the transmission antenna 911 to the space. Radiate.
　タグ９００は、受信アンテナ９０１においてＵＷＢパルスを受信し、タグＩＤ付加部９０３において各タグで固有のタグＩＤを用いてＵＷＢパルスに変調をかける。これにより、自装置のタグ識別用のＩＤ情報である識別ＩＤを付加し、送信アンテナ９０２から送出する。 The tag 900 receives the UWB pulse at the receiving antenna 901, and the tag ID adding unit 903 modulates the UWB pulse using a unique tag ID in each tag. As a result, an identification ID, which is ID information for tag identification of the own device, is added and transmitted from the transmission antenna 902.
　リーダ９１０は、受信アンテナ９１４においてタグ９００から返信される信号を受信し、パルス検出部９１５においてＵＷＢパルスを検出する。タグＩＤ検出部９１８においてＵＷＢパルスからタグＩＤを検出して、タグを装着した人間の個別認識を行う。そして、遅延時間測定部９１６において、タイミング信号出力部９１３のタイミング信号を基準としてタグ９００より返信されたＵＷＢパルスの遅延時間を測定し、距離算出部９１７において、前記測定されたＵＷＢパルスの遅延時間に基づきリーダとタグの距離を算出する。 The reader 910 receives a signal returned from the tag 900 at the reception antenna 914 and detects a UWB pulse at the pulse detection unit 915. The tag ID detection unit 918 detects the tag ID from the UWB pulse, and performs individual recognition of the person wearing the tag. Then, the delay time measurement unit 916 measures the delay time of the UWB pulse returned from the tag 900 with reference to the timing signal of the timing signal output unit 913, and the distance calculation unit 917 measures the measured delay time of the UWB pulse. Based on the above, the distance between the reader and the tag is calculated.
　なお、アクティブ方式の場合には、タグがあらかじめリーダと同期したタイミングでＩＤ情報を含む測定用信号を送出するか、タグとリーダが同期していない場合においては、複数リーダのクロックを同期させて、タグから複数リーダへＩＤ情報を含む測定用信号を送出し、この測定用信号が到達するまでに要した時間の差を求める。これにより、各リーダにおける相対的な伝搬時間（伝搬時間差）からタグ－リーダ間の測距を行うことができる。 In the case of the active method, a measurement signal including ID information is transmitted at the timing when the tag is synchronized with the reader in advance, or when the tag and the reader are not synchronized, the clocks of a plurality of readers are synchronized. Then, a measurement signal including ID information is transmitted from the tag to a plurality of readers, and a difference in time required until the measurement signal arrives is obtained. Thereby, distance measurement between the tag and the reader can be performed from the relative propagation time (propagation time difference) in each reader.
　ここで、複数のリーダが存在する場合には、三点測量の原理でタグの位置を測定することができる。また、リーダが電波の到来方向を測定する機能を有する場合には、リーダが１個であっても電波の到来方向とタグ－リーダ間の距離とからタグの位置を測定することができる。 Here, when there are a plurality of readers, the tag position can be measured by the principle of three-point surveying. Further, when the reader has a function of measuring the arrival direction of radio waves, the tag position can be measured from the arrival direction of radio waves and the distance between the tag and the reader even if there is only one reader.
　ＵＷＢを用いた無線測距システムにおいては、前述のように、リーダから見た可視領域にない陰領域では、人体の遮蔽吸収効果によりタグからの送信信号は大きく減衰する。このため、本実施の形態においては、人体に複数のタグを装着し、タグを装着して人体が様々な姿勢をとった際に、常にリーダから人体上の可視領域に単数または複数のタグが位置するように、すなわち少なくとも１つのタグがリーダから見える位置にタグを構成する。そして、リーダは、複数のタグのうち少なくとも１つのタグから送信されるタグＩＤを検知するか、またはタグＩＤに基づくリーダ－タグ間の距離測定を行う。 In the wireless ranging system using UWB, as described above, in the shadow area that is not in the visible area seen from the reader, the transmission signal from the tag is greatly attenuated due to the shielding absorption effect of the human body. For this reason, in the present embodiment, when a plurality of tags are attached to the human body, and the human body takes various postures by attaching the tags, the tag or tags are always present from the reader to the visible region on the human body. The tags are arranged so that they are located, i.e. where at least one tag is visible to the reader. Then, the reader detects a tag ID transmitted from at least one tag among the plurality of tags, or measures a distance between the reader and the tag based on the tag ID.
　本実施の形態では、一例として複数のタグが同一のタグＩＤを持つ場合について説明する。図８に示したように、第１のタグ８０１は、名札８１０の表面に搭載される。このタグ８０１には、名札８１０を装着した人間の個別認識を行うためのＩＤ情報としてタグＩＤが付与されている。タグ８０１がリーダ８００の受信エリアに入った時には、タグ８０１からリーダ８００に対してタグＩＤを含む信号が送信される。一方、第２のタグ８０２は、例えば名札８１０に接続された首かけひも８０３の中心部に装着される。人間が名札８１０を装着した時に、第２のタグ８０２が人間のちょうど首の後に接して位置するようにすることで、第２のタグ８０２は、第１のタグ８０１が搭載された名札８１０に対して、人間の裏側に搭載される。ここで、第２のタグ８０２も第１のタグ８０１と同じＩＤのタグＩＤを有する。 In this embodiment, a case where a plurality of tags have the same tag ID will be described as an example. As shown in FIG. 8, the first tag 801 is mounted on the surface of the name tag 810. A tag ID is assigned to the tag 801 as ID information for performing individual recognition of a person wearing the name tag 810. When the tag 801 enters the reception area of the reader 800, a signal including a tag ID is transmitted from the tag 801 to the reader 800. On the other hand, the second tag 802 is attached to, for example, the center of a neck strap 803 connected to the name tag 810. When the human wears the name tag 810, the second tag 802 is positioned in contact with the back of the person's neck, so that the second tag 802 is attached to the name tag 810 on which the first tag 801 is mounted. On the other hand, it is mounted on the back side of humans. Here, the second tag 802 also has the same tag ID as the first tag 801.
　リーダ８００は、第１のタグ８０１または第２のタグ８０２から送信される信号からタグＩＤを検出し、第１のタグと第２のタグを装着した人間の個別ＩＤを認識する。この際、リーダ８００に対して、第１のタグ８０１または第２のタグ８０２のどちらかが、リーダ８００の方向に向くことになるので、複数のタグから送信される複数の信号を選択または合成してタグＩＤを検知する。ＩＤ情報の識別においては、リーダ８００は、タグＩＤの読み取りを行い、その信号レベル等によって読み取りＩＤの信頼性を観測し、信頼性が高いデータを用いてタグＩＤと判定して個別認識を行う。また、タグとリーダとの距離算出においては、最短のルートを経て到達した電波により測定を行うため、識別したタグＩＤと同じと思われるＩＤに関して先頭波を検出して距離測定を行う。複数のタグのタグＩＤを同じＩＤとすることで、リーダにおいて複数タグに対応させる場合の付加機能が不要になる。 The reader 800 detects the tag ID from the signal transmitted from the first tag 801 or the second tag 802 and recognizes the individual ID of the person wearing the first tag and the second tag. At this time, since either the first tag 801 or the second tag 802 is directed toward the reader 800 with respect to the reader 800, a plurality of signals transmitted from a plurality of tags are selected or synthesized. The tag ID is detected. In identifying the ID information, the reader 800 reads the tag ID, observes the reliability of the read ID based on the signal level, etc., determines the tag ID using highly reliable data, and performs individual recognition. . In calculating the distance between the tag and the reader, since the measurement is performed using the radio wave that has arrived through the shortest route, the distance is measured by detecting the leading wave for the ID that seems to be the same as the identified tag ID. By setting the tag IDs of a plurality of tags to the same ID, an additional function in the case of corresponding to a plurality of tags in the reader becomes unnecessary.
　上記構成において、２つのタグの特性に関しては特に述べていないが、例えば名札とひもにタグを装着する場合においては、ひもと比較して名札は広い面積を有する。このため、名札はアンテナ等のタグの設計自由度を増すことができ、これにより、タグ送信電力の向上を図ることができる。また、この場合に、リーダにおいて名札のタグから送信された電波を優先的にタグＩＤと識別することにより、信頼性を向上させることができる。ここで、名札に装着されたタグとひもに装着されたタグとは、ＩＤ情報を含むデータ部にフラグを持たせることにより識別が可能となる。 In the above configuration, the characteristics of the two tags are not specifically described. For example, when a tag is attached to a name tag and a string, the name tag has a larger area than a string. For this reason, the name tag can increase the degree of freedom in designing a tag such as an antenna, thereby improving the tag transmission power. In this case, the reliability can be improved by preferentially identifying the radio wave transmitted from the tag of the name tag in the reader as the tag ID. Here, the tag attached to the name tag and the tag attached to the string can be identified by providing a flag in the data portion including the ID information.
　なお、本実施の形態においては、複数のタグは同一のタグＩＤを持つものとして説明したが、異なるタグＩＤを持つようにしてもよい。タグごとにＩＤ情報が異なる場合は、あらかじめタグを装着している人に対して、複数のタグＩＤが付加されていることを示す情報を登録しておくことにより、上記の同一ＩＤを持つタグにおける処理と同様な処理を行って同等の作用効果が得られる。また、上述したように、一例として名札に装着したタグのＩＤを優先的に検出する場合においては、あらかじめ名札のタグＩＤを登録しておき、リーダで該当ＩＤについて優先的に処理を行えばよい。 In the present embodiment, a plurality of tags have been described as having the same tag ID, but may have different tag IDs. If the ID information is different for each tag, the tag having the same ID is registered by registering information indicating that a plurality of tag IDs are added to a person who has already attached the tag. The same operation and effect can be obtained by performing the same process as in the above. In addition, as described above, when the ID of a tag attached to a name tag is preferentially detected as an example, the tag ID of the name tag may be registered in advance, and the reader may preferentially process the corresponding ID. .
　また、本実施の形態においては、第２のタグを名札のひもに装着する構成例を示したが、人間が着用する服の襟などに配置してもよい。例えば、工場等における作業着のように、着る人が決められている場合、服の襟部分などの後ろ側の部分にあらかじめ名札と同一ＩＤを有するタグを縫いつけておけば、同様の作用効果が得られる。 In the present embodiment, the configuration example in which the second tag is attached to the name tag string has been described. However, the second tag may be arranged on the collar of clothes worn by humans. For example, when the person to wear is decided like work clothes in a factory etc., if a tag having the same ID as the name tag is previously sewed on the back side portion such as the collar portion of the clothes, the same effect is obtained. can get.
　このように実施の形態２によれば、人体における遮蔽吸収効果を軽減でき、人体吸収損失の大きいＵＷＢ無線等を用いた場合において、タグ－リーダ間における識別ＩＤの送受信及び距離測定、測位を信頼性が高い状態で実現することができる。 As described above, according to the second embodiment, the shielding / absorbing effect in the human body can be reduced, and when the UWB wireless or the like having a large human body absorption loss is used, the identification ID is transmitted / received between the tag and the reader, the distance measurement, and the positioning are reliable. It can be realized in a state with high performance.
　（実施の形態３）
　図１０は、本発明の実施の形態３に係る無線測距システムの全体構成を示す図である。実施の形態３は、人間の頭部にタグを配置した例である。 (Embodiment 3)
FIG. 10 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 3 of the present invention. The third embodiment is an example in which a tag is arranged on a human head.
　無線測距システムは、リーダ８００、第１のタグ８０１、第２のタグ８０２を有して構成される。第１のタグ８０１は、実施の形態１と同様、人間８５０が身に着ける名札８１０に搭載されている。第２のタグ８０２は、人間８５０が頭にかぶるヘルメット１００５に装着されている。図の例では、ヘルメット１００５の頭頂部に第２のタグ１００２が装着されている。人間がヘルメット８０５をかぶった状態では、第２のタグ８０２は頭頂部に位置し、人体の前側にある名札８１０の可視領域から外れた人体の後方からの方向を含む、全方向から第２のタグ８０２が視認可能に配置されることになる。 The wireless ranging system includes a reader 800, a first tag 801, and a second tag 802. Similar to the first embodiment, the first tag 801 is mounted on a name tag 810 worn by a human 850. The second tag 802 is attached to the helmet 1005 worn by the human 850. In the illustrated example, the second tag 1002 is attached to the top of the helmet 1005. When the human is wearing the helmet 805, the second tag 802 is located at the top of the head, and includes the direction from the rear of the human body that is out of the visible region of the name tag 810 on the front side of the human body. The tag 802 is disposed so as to be visible.
　ヘルメット８０５は、人体の最上部にあるため人影になる状況が少なく、また物体衝突の衝撃から人間の頭部を守るため、頭部から若干の距離をおいて装着される。このため、実施の形態３では、人体における遮蔽吸収効果、及びアンテナの人体効果による特性劣化がさらに軽減される。実施の形態３においては、通常は第２のタグ８０２が主たるＩＤ取得及び距離測定用のタグとなるが、人間がヘルメット８０５を脱いでいる場合も想定され、その場合には主に第１のタグ８０１によるＩＤ取得及び距離測定が行われる。 The helmet 805 is placed at a slight distance from the head to protect the human head from the impact of an object collision because the helmet 805 is at the top of the human body and is less likely to become a human figure. For this reason, in Embodiment 3, the characteristic deterioration by the shielding absorption effect in a human body and the human body effect of an antenna is further reduced. In the third embodiment, the second tag 802 is usually the main ID acquisition and distance measurement tag, but it is also assumed that a person is taking off the helmet 805. In that case, the first tag is mainly used. ID acquisition and distance measurement are performed by the tag 801.
　（実施の形態４）
　図１１は、本発明の実施の形態４に係る無線測距システムの全体構成を示す図である。実施の形態４は、人間の胴体の前後にタグを配置した例である。 (Embodiment 4)
FIG. 11 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 4 of the present invention. The fourth embodiment is an example in which tags are arranged before and after a human torso.
　無線測距システムは、リーダ８００、第１のタグ１１０１、第２のタグ１１０２を有して構成される。第１のタグ１１０１は、人間８５０が身に着ける腰ベルト１１０３のバックル部分等に搭載され、第２のタグ１１０２は、この腰ベルト１１０３の異なる位置、例えば腰ベルト１１０３の中間部分に装着されている。人間８５０が腰ベルト１１０３を身に着けた状態では、腰ベルト１１０３の前後に第１のタグ１１０１、第２のタグ１１０２が位置し、第１のタグ１１０１が人体の前方に向かって配置され、第２のタグ８０２が人体の後方に向かって配置されることになる。 The wireless ranging system includes a reader 800, a first tag 1101, and a second tag 1102. The first tag 1101 is mounted on a buckle portion or the like of the waist belt 1103 worn by the human 850, and the second tag 1102 is mounted on a different position of the waist belt 1103, for example, at an intermediate portion of the waist belt 1103. Yes. When the human 850 wears the waist belt 1103, the first tag 1101 and the second tag 1102 are positioned before and after the waist belt 1103, and the first tag 1101 is disposed toward the front of the human body, The second tag 802 is arranged toward the back of the human body.
　第１のタグ１１０１は、腰ベルトの前方の例えばバックル部分に搭載することで、人間の腹部に当たる位置に装着される。第１のタグ１１０１には、腰ベルト１１０３を装着した人間の個別認識を行うためのＩＤ情報としてタグＩＤを付与しており、リーダ８００の受信エリアに入った時には、タグ１１０１からリーダ８００に対してタグＩＤを含む信号が送信される。一方、第２のタグ１１０２は、人間の背部や腰部に当たる位置に装着されるように、腰ベルト１１０３の中間部分に装着することで、第１のタグ１１０１に対して人間の裏側に搭載される。ここで、第２のタグ１１０２も第１のタグ１１０１と同じＩＤのタグＩＤを有する。 The first tag 1101 is mounted at a position corresponding to a human abdomen by mounting it on the buckle portion, for example, in front of the waist belt. A tag ID is assigned to the first tag 1101 as ID information for performing individual recognition of a human wearing the waist belt 1103. When the tag 1101 enters the reception area of the reader 800, the tag 1101 is connected to the reader 800. Then, a signal including the tag ID is transmitted. On the other hand, the second tag 1102 is mounted on the back side of the human body with respect to the first tag 1101 by being mounted on the middle portion of the waist belt 1103 so that the second tag 1102 is mounted on the back or waist of the human. . Here, the second tag 1102 also has the same tag ID as the first tag 1101.
　リーダ８００は、第１のタグ１１０１または第２のタグ１１０２から送信される信号からタグＩＤを検出し、第１のタグと第２のタグを装着した人間の個別ＩＤを認識する。この際、リーダ８００に対して、第１のタグ１１０１または第２のタグ１１０２のどちらかが、リーダ８００の方向に向くことになる。ＩＤ情報の識別においては、リーダ８００は、タグＩＤの読み取りを行い、その信号レベル等によって読み取りＩＤの信頼性を観測し、信頼性が高いものをタグＩＤと判定する。実施の形態４では、腰ベルト１１０３を介して第１のタグ１１０１と第２のタグ１１０２は一体化されており、常に人体の前後に装着される状態になり、遮蔽吸収効果を軽減できるという効果を有する。 The reader 800 detects the tag ID from the signal transmitted from the first tag 1101 or the second tag 1102 and recognizes the individual ID of the person wearing the first tag and the second tag. At this time, either the first tag 1101 or the second tag 1102 is directed toward the reader 800 with respect to the reader 800. In identifying the ID information, the reader 800 reads the tag ID, observes the reliability of the read ID based on the signal level or the like, and determines that the tag ID is highly reliable. In the fourth embodiment, the first tag 1101 and the second tag 1102 are integrated with each other through the waist belt 1103 and are always attached to the front and back of the human body, thereby reducing the shielding absorption effect. Have
　なお、本実施の形態では、２個のタグを設けた例を示しているが、ベルト周辺の２箇所以上に同一ＩＤを有するタグを２個以上、例えば３個、４個等のタグを等間隔に装着するようにしてもよい。この場合、人体における遮蔽吸収効果による特性劣化がより軽減される。また、実施の形態２に示したような名札やひもに装着したタグと、実施の形態４のベルトに装着したタグとを組み合わせることにより、上下方向の高さの違いによる伝搬劣化の要因を軽減することも可能である。なお、本実施の形態では、腰ベルトを例に挙げたが、サスペンダ（吊りベルト）などを用いて、人体の前後に第１のタグ及び第２のタグを装着できるようにしてもよい。 In this embodiment, an example in which two tags are provided is shown. However, two or more tags having the same ID are provided at two or more locations around the belt, for example, three, four, etc. tags. You may make it mount | wear with an interval. In this case, the characteristic deterioration due to the shielding absorption effect in the human body is further reduced. Further, by combining the tag attached to the name tag or string as shown in the second embodiment and the tag attached to the belt of the fourth embodiment, the cause of propagation deterioration due to the difference in height in the vertical direction is reduced. It is also possible to do. In the present embodiment, the waist belt is taken as an example. However, the first tag and the second tag may be attached to the front and back of the human body using a suspender (suspending belt) or the like.
　（実施の形態５）
　図１２は、本発明の実施の形態５に係る無線測距システムの全体構成を示す図である。実施の形態５は、人間の両肩にタグを配置した例である。 (Embodiment 5)
FIG. 12 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 5 of the present invention. The fifth embodiment is an example in which tags are arranged on both human shoulders.
　無線測距システムは、リーダ８００、第１のタグ１２０１、第２のタグ１２０２を有して構成される。第１のタグ１２０１は、人間８５０が身に着ける服の一方の肩に装着され、第２のタグ１２０２は、服の他方の肩に装着されている。人間８５０が服を身に着けた状態では、両肩に第１のタグ１２０１、第２のタグ１２０２が位置し、第１のタグ１２０１が人体の右側方に向かって配置され、第２のタグ１２０２が人体の左側方に向かって配置されることになる。ここで、第１のタグ１２０１と第２のタグ１２０２とは同じＩＤのタグＩＤを有する。 The wireless ranging system includes a reader 800, a first tag 1201, and a second tag 1202. The first tag 1201 is attached to one shoulder of the clothes worn by the human 850, and the second tag 1202 is attached to the other shoulder of the clothes. When the person 850 wears clothes, the first tag 1201 and the second tag 1202 are located on both shoulders, the first tag 1201 is arranged toward the right side of the human body, and the second tag 1202 is arranged toward the left side of the human body. Here, the first tag 1201 and the second tag 1202 have the same tag ID.
　これらの第１のタグ１２０１、第２のタグ１２０２は、例えば洋服や作業着上着の左右の肩パッド、軍服などの左右の肩章に装着することができる。タグを肩に装着した場合には、タグのアンテナ指向性パターンは主に上方の半球面を形成すると考えられ、特にリーダ８００が人間の肩の位置より上方にある場合には、人体の遮蔽吸収効果を受けにくい。ただし、人間の頭部とリーダ及びタグの位置関係によっては、電波が頭部により遮蔽吸収されるため、頭部の影響を考慮して、実施の形態５のように両肩にタグを装着することにより、頭部による遮蔽吸収を防ぐことができる。 These first tag 1201 and second tag 1202 can be attached to left and right shoulder pads such as left and right shoulder pads and military uniforms of clothes and work clothes, for example. When the tag is mounted on the shoulder, it is considered that the antenna directivity pattern of the tag mainly forms an upper hemispherical surface, particularly when the reader 800 is above the position of the human shoulder, It is hard to receive an effect. However, depending on the positional relationship between the human head, reader, and tag, radio waves are shielded and absorbed by the head, so the tag is attached to both shoulders as in the fifth embodiment in consideration of the effect of the head. Thus, shielding absorption by the head can be prevented.
　（実施の形態６）
　図１３は、本発明の実施の形態６に係る無線測距システムの全体構成を示す図である。実施の形態６は、人間の両腕と胸にタグを配置した例である。 (Embodiment 6)
FIG. 13 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 6 of the present invention. The sixth embodiment is an example in which tags are arranged on both human arms and chest.
　無線測距システムは、リーダ８００、第１のタグ１３０１、第２のタグ１３０２、第３のタグ１３０３を有して構成される。第１のタグ１３０１は、人間８５０が身に着ける服の左腕に装着され、第２のタグ１３０２は右腕に装着され、第３のタグ１３０３は胸に装着されている。人間８５０が服を身に着けた状態では、両腕に第１のタグ１３０１、第２のタグ１３０２が、胸部に第３のタグ１３０３がそれぞれ位置し、第１のタグ１３０１が人体の左側方に向かって配置され、第２のタグ１３０２が人体の右側方に向かって配置され、第３のタグ１３０３が人体の前方に向かって配置されることになる。 The wireless ranging system includes a reader 800, a first tag 1301, a second tag 1302, and a third tag 1303. The first tag 1301 is attached to the left arm of the clothes worn by the human 850, the second tag 1302 is attached to the right arm, and the third tag 1303 is attached to the chest. When the person 850 wears clothes, the first tag 1301 and the second tag 1302 are located on both arms, the third tag 1303 is located on the chest, and the first tag 1301 is located on the left side of the human body. The second tag 1302 is disposed toward the right side of the human body, and the third tag 1303 is disposed toward the front of the human body.
　ここで、第１のタグ１３０１、第２のタグ１３０２は、例えば左右の袖ボタンにそれぞれ配置する。第３のタグ１３０３は、例えば胸ポケットなどに装着する。なお、第１のタグは左袖ボタン、第２のタグは右袖ボタン、第３のタグは名札としてもよい。または、第１のタグは左袖ボタン、第２のタグは右袖ボタン、第３のタグは前ボタンとしてもよい。または、第１または第２のタグは腕時計に装着されていてもよい。 Here, the first tag 1301 and the second tag 1302 are arranged, for example, on the left and right sleeve buttons, respectively. The third tag 1303 is attached to, for example, a breast pocket. The first tag may be a left sleeve button, the second tag may be a right sleeve button, and the third tag may be a name tag. Alternatively, the first tag may be a left sleeve button, the second tag may be a right sleeve button, and the third tag may be a front button. Alternatively, the first or second tag may be attached to the watch.
　実施の形態６の場合、第１のタグのアンテナ指向性パターンは左方向の半球面、第２のタグのアンテナ指向性パターンは右方向の半球面、第３のタグのアンテナ指向性パターンは前方向の半球面を形成すると考えられる。これにより、リーダ－タグ間における人体の遮蔽吸収効果を軽減することができる。 In the case of the sixth embodiment, the antenna directivity pattern of the first tag is a left hemisphere, the antenna directivity pattern of the second tag is a right hemisphere, and the antenna directivity pattern of the third tag is the front. It is thought to form a hemispherical surface. As a result, the effect of shielding and absorbing the human body between the reader and the tag can be reduced.
　（実施の形態７）
　図１４は、本発明の実施の形態７に係る無線測距システムの全体構成を示す図である。実施の形態７は、人間の胸と足部にタグを配置した例である。 (Embodiment 7)
FIG. 14 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 7 of the present invention. The seventh embodiment is an example in which tags are arranged on a human chest and feet.
　無線測距システムは、リーダ８００、第１のタグ１４０１、第２のタグ１４０２を有して構成される。第１のタグ１４０１は、人間８５０が身に着ける名札８１０に装着され、第２のタグ１４０２は、足に履く靴１４１０の踵部分に装着されている。人間が名札８１０を身に着けて靴１４１０を履いた状態では、胸部に第１のタグ１４０１が、足部に第２のタグ１４０２がそれぞれ位置し、第１のタグ１４０１が人体の前方に向かって配置され、第２のタグ１４０２が人体の後方に向かって配置されることになる。ここで、第１のタグ１４０１と第２のタグ１４０２とは同じＩＤのタグＩＤを有する。 The wireless ranging system includes a reader 800, a first tag 1401, and a second tag 1402. The first tag 1401 is attached to a name tag 810 worn by a human 850, and the second tag 1402 is attached to a heel portion of a shoe 1410 worn on a foot. When a person wears a name tag 810 and a shoe 1410, the first tag 1401 is located on the chest, the second tag 1402 is located on the foot, and the first tag 1401 faces the front of the human body. The second tag 1402 is arranged toward the back of the human body. Here, the first tag 1401 and the second tag 1402 have the same tag ID.
　実施の形態７の場合、第１のタグのアンテナ指向性パターンは前方向に形成され、第２のタグのアンテナ指向性パターンは後方向に形成されることになる。これにより、第１のタグがリーダに対して反対方向に存在するときに、第２のタグはリーダ方向にそのアンテナ指向性パターンが向けられ、リーダ－タグ間でＩＤ取得及び距離測定が可能である。このように胸部と足部にタグを装着することにより、リーダ－タグ間における人体の遮蔽吸収効果を軽減することができる。 In the case of Embodiment 7, the antenna directivity pattern of the first tag is formed in the forward direction, and the antenna directivity pattern of the second tag is formed in the backward direction. As a result, when the first tag exists in the opposite direction to the reader, the antenna directivity pattern of the second tag is directed in the reader direction, and ID acquisition and distance measurement can be performed between the reader and the tag. is there. By attaching the tag to the chest and the foot in this manner, the effect of shielding and absorbing the human body between the reader and the tag can be reduced.
　図１４の例では、第２のタグ１４０２は靴の踵部分に装着しているが、靴ひもの部分に装着してもよい。靴ひもにタグを装着する場合には、タグを靴に縫い込む等の特別な装着構造を用いる必要が無く、一般の靴に後からタグを装着することが容易である。タグを靴に配置する場合は、靴ひもに装着してもアンテナ指向性パターンを後方にも向けることが可能である。 In the example of FIG. 14, the second tag 1402 is attached to the shoe heel portion, but may be attached to the shoelace portion. When the tag is attached to the shoelace, it is not necessary to use a special attachment structure such as sewing the tag into the shoe, and it is easy to attach the tag to a general shoe later. When the tag is arranged on the shoe, the antenna directivity pattern can be directed backward even when the tag is attached to the shoelace.
　（実施の形態８）
　図１５は、本発明の実施の形態８に係る無線測距システムの全体構成を示す図である。実施の形態８は、人間が装着するめがねの両側にタグを配置した例である。 (Embodiment 8)
FIG. 15 is a diagram showing an overall configuration of a wireless ranging system according to Embodiment 8 of the present invention. Embodiment 8 is an example in which tags are arranged on both sides of glasses worn by humans.
　無線測距システムは、リーダ８００、第１のタグ１５０１、第２のタグ１５０２を有して構成される。第１のタグ１５０１は、人間８５０が頭部にかけるめがね１５０３の右側の柄の部分に取り付けられ、第１のタグ１５０２は、そのめがね１５０３の左側の柄の部分に取り付けられている。 The wireless ranging system includes a reader 800, a first tag 1501, and a second tag 1502. The first tag 1501 is attached to the handle portion on the right side of the glasses 1503 that the human 850 puts on the head, and the first tag 1502 is attached to the handle portion on the left side of the glasses 1503.
　実施の形態８の場合、第１のタグ１５０１のアンテナ指向性パターンは右方向の半球面、第２のタグ１５０２のアンテナ指向性パターンは左方向の半球面を形成すると考えられ、リーダ－タグ間における人体頭部の遮蔽吸収効果を軽減することができる。めがねとしては、一般のめがねの他、スキーゴーグル、工場作業における防御作業ゴーグルなどを例として挙げることができる。 In the case of Embodiment 8, it is considered that the antenna directivity pattern of the first tag 1501 forms a right hemisphere, and the antenna directivity pattern of the second tag 1502 forms a left hemisphere. It is possible to reduce the effect of shielding and absorbing the human head at. Examples of glasses include general goggles, ski goggles, defensive work goggles in factory work, and the like.
　以上説明したように、実施の形態２～８では、同じＩＤを有する第１のタグと第２のタグなど、複数のタグを人間の前後、左右などの複数の箇所に設け、複数のタグが、人間の正面、背面、頭部、足部、左側、右側から選択される少なくとも２箇所（好ましくは２～３箇所）に配置されるように構成する。このように、複数のタグが人体を介して反対側に位置するなど、人体に対して異なる方向に向かうように配置することにより、少なくとも１つのタグが基地局に向くように配置されるので、少なくとも１つのタグと基地局との間に人体が介在しない状態で無線通信が可能になる。したがって、人体の遮蔽吸収効果を軽減でき、人体吸収による信号強度劣化を補うことができる。これによって、人体吸収損失の大きいＵＷＢを用いるＵＷＢリーダタグ装置などの無線測距システムにおいて、信頼性の高い無線通信を可能とし、タグＩＤの送受信及びリーダ－タグ間の距離測定を確実に行うことが可能になる。 As described above, in Embodiments 2 to 8, a plurality of tags, such as a first tag and a second tag having the same ID, are provided at a plurality of locations such as front and back, left and right of a human, It is configured to be arranged in at least two locations (preferably 2 to 3 locations) selected from the front, back, head, feet, left side, and right side of a human. In this way, by arranging the plurality of tags to face different directions with respect to the human body, such as being positioned on the opposite side via the human body, at least one tag is arranged to face the base station, Wireless communication is possible without a human body between at least one tag and the base station. Therefore, the shielding / absorbing effect of the human body can be reduced, and signal strength deterioration due to human body absorption can be compensated. As a result, in a wireless ranging system such as a UWB reader tag device using UWB having a large human body absorption loss, highly reliable wireless communication can be performed, and tag ID transmission / reception and reader-tag distance measurement can be reliably performed. It becomes possible.
　上記実施の形態２～８の説明から導出される技術的思想は以下の通りである。 The technical idea derived from the description of Embodiments 2 to 8 is as follows.
　（１）基地局と無線端末とを備える無線測距システムに用いられる無線端末であって、複数のタグを有して構成され、前記複数のタグの各々は、前記無線端末の装着対象の個別認識を行うための識別ＩＤを含む信号を送信可能であり、前記無線端末を人体に装着したときに、前記複数のタグが、人間の正面、背面、頭部、足部、左側、右側から選択される少なくとも２箇所に配置される無線端末。 (1) A wireless terminal used in a wireless ranging system including a base station and a wireless terminal, and includes a plurality of tags, and each of the plurality of tags is an individual to which the wireless terminal is attached. A signal including an identification ID for recognition can be transmitted, and when the wireless terminal is mounted on a human body, the plurality of tags are selected from the front, back, head, foot, left side, and right side of the human Wireless terminals arranged in at least two places.
　（２）ウルトラワイドバンド無線（ＵＷＢ）方式を用いて前記基地局と通信を行う（１）に記載の無線端末。 (2) The wireless terminal according to (1), which communicates with the base station using an ultra-wide band wireless (UWB) system.
　（３）前記複数のタグは、同一の識別ＩＤを有する（１）または（２）に記載の無線端末。 (3) The wireless terminal according to (1) or (2), wherein the plurality of tags have the same identification ID.
　（４）前記複数のタグとして、前記無線端末を装着する人間の名札の表面に配置される第１のタグと、前記人間の背面に配置される第２のタグとを有し、前記第１のタグと前記第２のタグは、同一の識別ＩＤを有し、前記第１のタグまたは第２のタグから送信される信号が、前記無線端末を装着する人間の個別認識を行うために用いられる（１）乃至（３）のいずれか一項に記載の無線端末。 (4) As the plurality of tags, a first tag disposed on a surface of a human name tag on which the wireless terminal is mounted, and a second tag disposed on a back surface of the human, the first tag The tag and the second tag have the same identification ID, and a signal transmitted from the first tag or the second tag is used for individual recognition of a person wearing the wireless terminal. The wireless terminal according to any one of (1) to (3).
　（５）前記第２のタグは、前記名札に接続された輪状の紐の、前記名札との接続位置とは異なる位置に配置される（４）に記載の無線端末。 (5) The wireless terminal according to (4), wherein the second tag is arranged at a position different from a connection position of the ring-shaped string connected to the name tag with the name tag.
　（６）前記複数のタグのうちの１つは、人間が頭部に装着するヘルメットに配置される（１）乃至（３）のいずれか一項に記載の無線端末。 (6) The wireless terminal according to any one of (1) to (3), wherein one of the plurality of tags is arranged in a helmet worn by a human being on a head.
　（７）前記無線端末は人間が装着する腰ベルト上に配置されるものであり、前記複数のタグは、前記腰ベルトを人体に装着したときに、異なる位置に配置される（１）乃至（３）のいずれか一項に記載の無線端末。 (7) The wireless terminal is disposed on a waist belt worn by a human, and the plurality of tags are disposed at different positions when the waist belt is worn on a human body. The wireless terminal according to any one of 3).
　（８）前記複数のタグのうち１つは、人間が腕に装着する腕時計に配置される（１）乃至（３）のいずれか一項に記載の無線端末。 (8) The wireless terminal according to any one of (1) to (3), wherein one of the plurality of tags is arranged on a wristwatch worn by a human being on an arm.
　（９）前記複数のタグとして、前記無線端末を装着する人間の右肩に配置される第１のタグと、左肩に配置される第２のタグとを有し、前記第１のタグと前記第２のタグは、同一の識別ＩＤを有する（１）乃至（３）のいずれか一項に記載の無線端末。 (9) As the plurality of tags, a first tag disposed on a right shoulder of a person wearing the wireless terminal, and a second tag disposed on a left shoulder, the first tag and the The wireless tag according to any one of (1) to (3), wherein the second tag has the same identification ID.
　（１０）前記複数のタグとして、前記無線端末を装着する人間が着用する服の左袖ボタンに配置される第１のタグと、右袖ボタンに配置される第２のタグと、前ボタンに配置される第３のタグとを有する（１）乃至（３）のいずれか一項に記載の無線端末。 (10) As the plurality of tags, a first tag arranged on a left sleeve button of clothes worn by a person wearing the wireless terminal, a second tag arranged on a right sleeve button, and a front button The wireless terminal according to any one of (1) to (3), further including a third tag arranged.
　（１１）前記複数のタグとして、人間が頭部に装着するメガネの右側の柄に配置される第１のタグと、左側の柄に配置される第２のタグとを有する（１）乃至（３）のいずれか一項に記載の無線端末。 (11) The plurality of tags include a first tag disposed on a right handle of glasses worn by a human on a head and a second tag disposed on a left handle (1) to ( The wireless terminal according to any one of 3).
　（１２）前記複数のタグとして、前記無線端末を装着する人間の名札に配置される第１のタグと、靴の踵部に配置される第２のタグとを有し、前記第１のタグと前記第２のタグは、同一の識別ＩＤを有する（１）乃至（３）のいずれか一項に記載の無線端末。 (12) As the plurality of tags, a first tag disposed on a name tag of a person wearing the wireless terminal and a second tag disposed on a heel of a shoe, the first tag The wireless terminal according to any one of (1) to (3), wherein the second tag has the same identification ID.
　（１３）前記複数のタグとして、前記無線端末を装着する人間の名札に配置される第１のタグと、前記人間が着用する服の襟に配置される第２のタグとを有し、前記第１のタグと前記第２のタグは、同一の識別ＩＤを有する（１）乃至（３）のいずれか一項に記載の無線端末。 (13) The plurality of tags include a first tag arranged on a name tag of a person wearing the wireless terminal, and a second tag arranged on a collar of clothes worn by the person, The wireless tag according to any one of (1) to (3), wherein the first tag and the second tag have the same identification ID.
　（１４）前記無線端末を人体に装着したときに、前記複数のタグは、その少なくとも１つが前記人体の可視領域に配置される（１）乃至（１３）のいずれか一項に記載の無線端末。 (14) The wireless terminal according to any one of (1) to (13), wherein when the wireless terminal is attached to a human body, at least one of the plurality of tags is arranged in a visible region of the human body. .
　（１５）基地局と無線端末とを備える無線測距システムに用いられる基地局であって、前記無線端末として、装着対象の個別認識を行うための識別ＩＤを含む信号を各々が送信することができる複数のタグを有し、前記無線端末を人体に装着したときに、前記複数のタグが、人間の正面、背面、頭部、足部、左側、右側から選択される少なくとも２箇所に配置されるものとの間で通信を行い、前記複数のタグのうち少なくとも１つから送信される信号に含まれる前記識別ＩＤを検知し、前記検知された識別ＩＤに基づいて、前記無線端末との距離を測定する基地局。 (15) A base station used in a wireless ranging system including a base station and a wireless terminal, each transmitting a signal including an identification ID for performing individual recognition of a wearing target as the wireless terminal. A plurality of tags, and when the wireless terminal is mounted on a human body, the plurality of tags are arranged in at least two locations selected from the front, back, head, foot, left side, and right side of a human. Communicating with the one, detecting the identification ID included in a signal transmitted from at least one of the plurality of tags, and based on the detected identification ID, the distance to the wireless terminal Measuring base station.
　（１６）前記複数のタグから送信される複数の信号を選択または合成し、前記識別ＩＤを検知する（１５）に記載の基地局。 (16) The base station according to (15), wherein a plurality of signals transmitted from the plurality of tags are selected or combined, and the identification ID is detected.
　（１７）前記複数のタグから送信される複数の信号に含まれる前記識別ＩＤの検知結果のうち、信頼性の高いデータを用いて識別ＩＤを判定し、前記無線端末を装着する人間の個別認識を行う（１５）または（１６）に記載の基地局。 (17) Individual identification of a human wearing the wireless terminal by determining the identification ID using highly reliable data among the detection results of the identification ID included in the plurality of signals transmitted from the plurality of tags. The base station according to (15) or (16).
　（１８）前記複数のタグから送信される複数の信号に含まれる前記識別ＩＤの検知結果のうち、信頼性の高いデータを用いて識別ＩＤを判定し、前記無線端末を装着する人間の個別認識を行った後に、前記検知された識別ＩＤと同じ識別ＩＤに関して、前記複数のタグから送信される信号の先頭波を用いて前記無線端末との距離を測定する（１５）または（１６）に記載の基地局。 (18) Of the detection results of the identification ID included in the plurality of signals transmitted from the plurality of tags, the identification ID is determined using highly reliable data, and the individual recognition of the human wearing the wireless terminal (15) or (16), wherein the distance from the wireless terminal is measured using the first wave of signals transmitted from the plurality of tags with respect to the same identification ID as the detected identification ID. Base station.
　（１９）複数のタグを有して構成され、前記複数のタグの各々は、前記無線端末の装着対象の個別認識を行うための識別ＩＤを含む信号を送信可能であり、前記無線端末を人体に装着したときに、前記複数のタグが、人間の正面、背面、頭部、足部、左側、右側から選択される少なくとも２箇所に配置される無線端末と、前記無線端末との間で通信を行い、前記複数のタグのうち少なくとも１つから送信される信号に含まれる前記識別ＩＤを検知し、前記検知された識別ＩＤに基づいて、前記無線端末との距離を測定する基地局と、を備える無線側距システム。 (19) A plurality of tags are configured, and each of the plurality of tags can transmit a signal including an identification ID for performing individual recognition of a mounting target of the wireless terminal. When mounted on the wireless terminal, the plurality of tags communicates between the wireless terminal and the wireless terminal disposed at least at two locations selected from the front, back, head, foot, left side, and right side of the human A base station that detects the identification ID included in a signal transmitted from at least one of the plurality of tags, and measures a distance from the wireless terminal based on the detected identification ID; A wireless lateral distance system.
　なお、本発明は、上記各実施の形態において示されたものに限定されるものではなく、明細書の記載、並びに周知の技術に基づいて、当業者が変更、応用することも本発明の予定するところであり、保護を求める範囲に含まれる。 Note that the present invention is not limited to those shown in the above embodiments, and those skilled in the art can also make changes and applications based on the description and well-known techniques. This is within the scope of seeking protection.
　また、上記各実施の形態では、無線測距システムに用いられる無線端末及び基地局として、無線端末である複数のタグと基地局であるリーダとを有し、ＵＷＢ無線方式を用いる無線測距システムの構成例を示したが、このような無線測距システムは、ＵＷＢリーダタグ装置と呼ばれることもある。 In each of the above-described embodiments, a wireless ranging system using a UWB wireless system having a plurality of tags as wireless terminals and a reader as a base station as wireless terminals and base stations used in the wireless ranging system Although such a configuration example is shown, such a wireless ranging system may be called a UWB reader tag device.
　また、本発明は、無線端末、基地局のそれぞれにおいて、ハードウェアで構成することも可能であるし、ソフトウェアで実現することも可能である。 Further, the present invention can be configured by hardware in each of the wireless terminal and the base station, and can also be realized by software.
　また、上記各実施の形態の説明に用いた各機能ブロックは、典型的には集積回路であるＬＳＩとして実現される。これらは個別に１チップ化されてもよいし、一部または全てを含むように１チップ化されてもよい。ここでは、ＬＳＩとしたが、集積度の違いにより、ＩＣ、システムＬＳＩ、スーパーＬＳＩ、ウルトラＬＳＩと呼称されることもある。 Further, each functional block used in the description of each of the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.
　また、集積回路化の手法はＬＳＩに限るものではなく、専用回路または汎用プロセッサで実現してもよい。ＬＳＩ製造後に、プログラムすることが可能なＦＰＧＡ（Field Programmable Gate Array）や、ＬＳＩ内部の回路セルの接続や設定を再構成可能なリコンフィギュラブル・プロセッサを利用してもよい。 Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.
　さらには、半導体技術の進歩または派生する別技術によりＬＳＩに置き換わる集積回路化の技術が登場すれば、当然、その技術を用いて機能ブロックの集積化を行ってもよい。バイオ技術の適応等が可能性としてありえる。 Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to integrate functional blocks using this technology. Biotechnology can be applied.
　２００８年１０月９日出願の特願２００８－２６２８７３及び２００８年１０月２４日出願の特願２００８－２７４５２４の日本出願に含まれる明細書、図面及び要約書の開示内容は、すべて本願に援用される。 The disclosures of the description, drawings and abstract contained in Japanese Patent Application No. 2008-262873 filed on Oct. 9, 2008 and Japanese Patent Application No. 2008-274524 filed on Oct. 24, 2008 are all incorporated herein by reference. The
　本発明にかかる基地局装置及び測距方法は、リモコン、名札等に装着されたタグのロケータ等に適用できる。
  The base station apparatus and distance measuring method according to the present invention can be applied to a tag locator attached to a remote controller, a name tag, or the like.

Claims (7)

  1. 　基地局装置を識別するためのＰビット（Ｐは自然数）からなる符号列で示されるリーダＩＤと、無線端末を識別するためのＱビット（Ｑは自然数）からなる符号列で示されるタグＩＤとを用いる無線測距システムにおける基地局装置であって、
    　Ｐ個のパルスを含み、前記リーダＩＤを示すＰビットの各々が１か０かによって各パルスがオンオフ変調されるユニークワードを生成し、前記ユニークワードを２×Ｍ個含むフレームを生成し、前記フレームをＱ個含むバーストを生成し、前記バーストを複数個含む送信信号を出力するパルス発生手段と、
    　前記無線端末が前記タグＩＤを示すＱビットの各々が１か０かに基づいて前記送信信号を変調した信号を、送信クロック周期のＭ分の１（Ｍは１以上の整数）ずつ位相の異なるタイミングで、サンプリング受信する受信手段と、
    　を具備する基地局装置。     A reader ID indicated by a code string consisting of P bits (P is a natural number) for identifying a base station apparatus, and a tag ID indicated by a code string consisting of Q bits (Q is a natural number) for identifying a wireless terminal A base station apparatus in a wireless ranging system using
    Generating a unique word including P pulses, each pulse being on-off modulated depending on whether each of the P bits indicating the reader ID is 1 or 0, and generating a frame including 2 × M unique words, Pulse generating means for generating a burst including Q frames and outputting a transmission signal including a plurality of the bursts;
    A signal obtained by modulating the transmission signal based on whether each of the Q bits indicating the tag ID is 1 or 0 by the wireless terminal has a phase difference of 1 / M (M is an integer of 1 or more) of the transmission clock period. Receiving means for receiving sampling at timing;
    A base station apparatus comprising:
  2. 　前記リーダＩＤと受信信号との相関演算を行い、遅延プロファイルを生成するリーダＩＤ相関演算手段を具備する請求項１に記載の基地局装置。 The base station apparatus according to claim 1, further comprising reader ID correlation calculation means for calculating a correlation between the reader ID and the received signal and generating a delay profile.
  3. 　前記リーダＩＤ相関演算手段は、Ｍ位相成分を全て加算して電力を増幅させて、前記相関演算を行う請求項２に記載の基地局装置。 The base station apparatus according to claim 2, wherein the reader ID correlation calculation means performs the correlation calculation by adding all M phase components to amplify power.
  4. 　前記遅延プロファイルを時系列的に蓄積し、蓄積した前記遅延プロファイルと所望のタグのタグＩＤとの相関演算を行うタグＩＤ相関演算手段と、
    　前記タグＩＤ相関演算手段による相関演算結果に基づいて、タグＩＤの先頭波を検出する先頭波検出手段と、
    　検出された前記先頭波の往復遅延時間を測定する遅延時間測定手段と、
    　測定された前記往復遅延時間から前記タグ及び前記リーダ間の距離を算出する距離算出手段と、
    　を具備する請求項２に記載の基地局装置。     Tag ID correlation calculation means for storing the delay profile in time series and performing a correlation calculation between the stored delay profile and a tag ID of a desired tag;
    First wave detection means for detecting the first wave of the tag ID based on the correlation calculation result by the tag ID correlation calculation means;
    A delay time measuring means for measuring a round trip delay time of the detected leading wave;
    Distance calculating means for calculating a distance between the tag and the reader from the measured round-trip delay time;
    The base station apparatus according to claim 2, comprising:
  5. 　前記無線端末が前記送信信号をするのに用いる変調方式はＡＳＫ変調である
    　請求項２乃至４いずれか一項に記載の基地局装置。     The base station apparatus as described in any one of Claims 2 thru | or 4. The modulation system used for the said radio | wireless terminal to transmit the said transmission signal is ASK modulation.
  6. 　基地局装置を識別するためのＰビット（Ｐは自然数）からなる符号列で示されるリーダＩＤと、無線端末を識別するためのＱビット（Ｑは自然数）からなる符号列で示されるタグＩＤとを用いる無線測距システムの前記基地局装置における測距方法であって、
    　Ｐ個のパルスを含み、前記リーダＩＤを示すＰビットの各々が１か０かによって各パルスがオンオフ変調されるユニークワードを生成し、前記ユニークワードを２×Ｍ個含むフレームを生成し、前記フレームをＱ個含むバーストを生成し、前記バーストを複数個含む送信信号を出力し、
    　前記無線端末が前記タグＩＤを示すＱビットの各々が１か０かに基づいて前記送信信号をＡＳＫ変調した信号を、送信クロック周期のＭ分の１（Ｍは１以上の整数）ずつ位相の異なるタイミングで、サンプリング受信する
    　測距方法。     A reader ID indicated by a code string consisting of P bits (P is a natural number) for identifying a base station apparatus, and a tag ID indicated by a code string consisting of Q bits (Q is a natural number) for identifying a wireless terminal A ranging method in the base station apparatus of a wireless ranging system using
    Generating a unique word including P pulses, each pulse being on-off modulated depending on whether each of the P bits indicating the reader ID is 1 or 0, and generating a frame including 2 × M unique words, Generating a burst including Q frames, and outputting a transmission signal including a plurality of the bursts;
    A signal obtained by ASK modulating the transmission signal based on whether each of the Q bits indicating the tag ID is 1 or 0 by the wireless terminal has a phase of 1 / M (M is an integer of 1 or more) of the transmission clock period. Ranging method that receives sampling at different timings.
  7. 　前記無線端末が前記送信信号をするのに用いる変調方式はＡＳＫ変調である
    　請求項６に記載の測距方法。     The ranging method according to claim 6, wherein a modulation scheme used by the wireless terminal to transmit the transmission signal is ASK modulation.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101944927A (en) * 2010-09-08 2011-01-12 中国人民解放军重庆通信学院 Comparison detecting technology for ultra wide band pulse
JP2017501509A (en) * 2013-10-13 2017-01-12 マイラップス ビーブイ Wearable sports timing tag assembly
JP2018102954A (en) * 2018-02-26 2018-07-05 マイラップス ビーブイ Wearable sport timing tag assembly
JP2019522187A (en) * 2016-06-02 2019-08-08 ノキア テクノロジーズ オーユー Apparatus and related methods

Families Citing this family (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120095673A1 (en) * 2010-10-13 2012-04-19 Electronics And Telecommunications Research Institute Apparatus and method for providing driving information for vehicles based on high speed movement long distance impuse radio ultra wideband
DE102012103085B4 (en) * 2011-04-12 2023-02-02 Electronics And Telecommunications Research Institute radar device
JP6116126B2 (en) * 2012-03-29 2017-04-19 パナソニック株式会社 Radar equipment
US9413418B2 (en) * 2012-07-12 2016-08-09 Datalogic Ip Tech S.R.L. Synchronization of a real-time UWB locating system
US10437658B2 (en) 2013-06-06 2019-10-08 Zebra Technologies Corporation Method, apparatus, and computer program product for collecting and displaying sporting event data based on real time data for proximity and movement of objects
US10609762B2 (en) 2013-06-06 2020-03-31 Zebra Technologies Corporation Method, apparatus, and computer program product improving backhaul of sensor and other data to real time location system network
US11423464B2 (en) 2013-06-06 2022-08-23 Zebra Technologies Corporation Method, apparatus, and computer program product for enhancement of fan experience based on location data
US9715005B2 (en) 2013-06-06 2017-07-25 Zih Corp. Method, apparatus, and computer program product improving real time location systems with multiple location technologies
US9699278B2 (en) 2013-06-06 2017-07-04 Zih Corp. Modular location tag for a real time location system network
US9517417B2 (en) 2013-06-06 2016-12-13 Zih Corp. Method, apparatus, and computer program product for performance analytics determining participant statistical data and game status data
US20140361890A1 (en) 2013-06-06 2014-12-11 Zih Corp. Method, apparatus, and computer program product for alert generation using health, fitness, operation, or performance of individuals
US9668164B2 (en) 2014-06-05 2017-05-30 Zih Corp. Receiver processor for bandwidth management of a multiple receiver real-time location system (RTLS)
US9626616B2 (en) 2014-06-05 2017-04-18 Zih Corp. Low-profile real-time location system tag
US9661455B2 (en) 2014-06-05 2017-05-23 Zih Corp. Method, apparatus, and computer program product for real time location system referencing in physically and radio frequency challenged environments
GB2542298B (en) 2014-06-05 2021-01-20 Zebra Tech Corp Method for iterative target location in a multiple receiver target location system
DE112015002651B4 (en) 2014-06-05 2023-02-16 Zebra Technologies Corporation Systems, apparatus and methods for variable rate ultra wideband communications
WO2015186044A1 (en) 2014-06-05 2015-12-10 Zih Corp. Receiver processor for adaptive windowing and high-resolution toa determination in a multiple receiver target location system
US20150375083A1 (en) 2014-06-05 2015-12-31 Zih Corp. Method, Apparatus, And Computer Program Product For Enhancement Of Event Visualizations Based On Location Data
US9759803B2 (en) 2014-06-06 2017-09-12 Zih Corp. Method, apparatus, and computer program product for employing a spatial association model in a real time location system
CN113050031A (en) 2014-06-06 2021-06-29 斑马技术公司 Method, apparatus and computer program product for improving a real-time location system utilizing multiple location technologies
EP3021255A1 (en) 2014-11-11 2016-05-18 Primetals Technologies Austria GmbH Identification tag for attachment to a metallurgical vessel, reading station and method for determining a wear status for the identification tag
EP3410147A4 (en) * 2016-01-29 2019-01-02 Panasonic Intellectual Property Management Co., Ltd. Distance measurement device
US10825311B2 (en) * 2018-01-09 2020-11-03 Wells Lamont Industry Group Llc Smart personal protective equipment
US10495737B1 (en) 2019-02-07 2019-12-03 Clairvoyant Networks, LLC Methods, systems, and computer readable media for time-slotted ultra-wide-band object tracking
US10567035B1 (en) 2019-03-06 2020-02-18 Clairvoyant Networks, LLC Methods, systems, and computer readable media for distribution of time synchronization information to ultra-wide-band devices
US10484833B1 (en) 2019-04-12 2019-11-19 Clairvoyant Networks, LLC Methods, systems and computer readable media for providing and using ultra wideband local area networks (LANs)
IL308434A (en) * 2021-05-12 2024-01-01 A D Knight Ltd Content based synchronization of similar data packets received by unsynchronized wireless receivers
KR102615140B1 (en) 2021-07-30 2023-12-19 부산대학교 산학협력단 Apparatus and method of ultrasonic distance measurement for reducing crosstalk, ultrasonic receiver for reducing crosstalk

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5596470A (en) * 1979-01-19 1980-07-22 Nec Corp Compressing device of encoded pulse
JPH01219687A (en) * 1988-02-29 1989-09-01 Sharp Corp Moving body discriminating apparatus
JPH05297129A (en) * 1992-04-21 1993-11-12 Clarion Co Ltd Distance measuring device
JP2005318553A (en) * 2004-03-29 2005-11-10 Brother Ind Ltd Position detection system, response device, position detection method, position detection program and information recording medium
WO2007072563A1 (en) * 2005-12-22 2007-06-28 Matsushita Electric Industrial Co., Ltd. Rfid system and rfid reading apparatus

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5938780A (en) * 1997-09-19 1999-08-17 Teradyne, Inc. Method for capturing digital data in an automatic test system
EP1732239A4 (en) * 2004-03-17 2007-12-26 Brother Ind Ltd Position detection system, response device and query device, radio communication system, position detection method, position detection program, and information recording medium
US7423576B2 (en) * 2006-07-24 2008-09-09 Mitsubishi Electric Research Laboratories, Inc. System and method for radar tracking using communications packets
JP5297129B2 (en) 2008-09-22 2013-09-25 パナソニック株式会社 Non-contact power feeding device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5596470A (en) * 1979-01-19 1980-07-22 Nec Corp Compressing device of encoded pulse
JPH01219687A (en) * 1988-02-29 1989-09-01 Sharp Corp Moving body discriminating apparatus
JPH05297129A (en) * 1992-04-21 1993-11-12 Clarion Co Ltd Distance measuring device
JP2005318553A (en) * 2004-03-29 2005-11-10 Brother Ind Ltd Position detection system, response device, position detection method, position detection program and information recording medium
WO2007072563A1 (en) * 2005-12-22 2007-06-28 Matsushita Electric Industrial Co., Ltd. Rfid system and rfid reading apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101944927A (en) * 2010-09-08 2011-01-12 中国人民解放军重庆通信学院 Comparison detecting technology for ultra wide band pulse
CN101944927B (en) * 2010-09-08 2014-05-14 中国人民解放军重庆通信学院 Comparison detecting technology for ultra wide band pulse
JP2017501509A (en) * 2013-10-13 2017-01-12 マイラップス ビーブイ Wearable sports timing tag assembly
US10671820B2 (en) 2013-10-13 2020-06-02 Mylaps B.V. Wearable sports timing tag assembly
JP2019522187A (en) * 2016-06-02 2019-08-08 ノキア テクノロジーズ オーユー Apparatus and related methods
JP2018102954A (en) * 2018-02-26 2018-07-05 マイラップス ビーブイ Wearable sport timing tag assembly

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